Information processing apparatus, information processing method, and recording medium

ABSTRACT

[Subject] 
     To generate a value unique to a solid-state imaging apparatus utilizing a physical feature of the solid-state imaging apparatus. 
     [Solving Means] 
     An information processing apparatus including a specification section specifying, from among a plurality of blocks that are set by dividing pixels included in at least a partial region of a pixel region having a plurality of pixels arrayed therein and each of which includes at least one or more of the pixels, at least one or more of the blocks, and a generation section generating a unique value based on pixel values of the pixels included in the specified blocks and a dispersion of the pixel values of the pixels among the plurality of blocks.

TECHNICAL FIELD

The present disclosure relates to an information processing apparatus,an information processing method, and a recording medium.

BACKGROUND ART

As a solid-state imaging apparatus, amplification type solid-stateimaging apparatuses represented by a MOS type image sensor such as aCMOS (Complementary Metal Oxide Semiconductor) image sensor are known.Further, charge transfer type solid-state imaging apparatusesrepresented by a CCD (Charge Coupled Device) image sensor are known.Such solid-state imaging apparatuses are widely used in digital stillcameras, digital video cameras and so forth. In recent years, as asolid-state imaging apparatus incorporated in a mobile apparatus such asa camera-equipped mobile phone or a PDA (Personal Digital Assistant), aMOS type image sensor is frequently used from the point of view of alower power supply voltage and power consumption. For example, PTL 1discloses an example of a digital camera to which such a solid-stateimaging apparatus as described above is applied.

A solid-state imaging apparatus of the MOS type includes a pixel array(pixel region) in which a unit pixel includes a photodiode that servesas a photoelectric conversion section and a plurality of pixeltransistors and a plurality of such unit pixels are arrayed in atwo-dimensional array, and a peripheral circuit region. The plurality ofpixel transistors include MOS transistors and each include threetransistors of a transfer transistor, a reset transistor and anamplification transistor or four transistors additionally including aselection transistor.

CITATION LIST Patent Literature [PTL 1]

-   -   Japanese Patent Laid-Open No. 2004-173154

SUMMARY Technical Problem

Incidentally, in recent years, a technology for outputting a valueunique to a device utilizing a physical feature difficult to duplicatecalled PUF (Physically Unclonable Function) is noticed. It is expectedthat, since such a value unique to a device generated utilizing the PUFas just described has a characteristic that it is difficult toduplicate, it is utilized, for example, as an identifier (ID) foridentifying an individual device or as so-called key information (forexample, a key for encryption).

Therefore, the present disclosure proposes an information processingapparatus, an information processing method, and a recording medium thatcan generate a value unique to a solid-state imaging apparatus utilizinga physical feature of the solid-state imaging apparatus.

Solution to Problem

According to the present disclosure, there is provided an informationprocessing apparatus including a specification section and a generationsection. The specification section specifies, from among a plurality ofblocks that are set by dividing pixels included in at least a partialregion of a pixel region having a plurality of pixels arrayed thereinand each of which includes at least one or more of the pixels, at leastone or more of the blocks. The generation section generates a uniquevalue based on pixel values of the pixels included in the specifiedblocks and a dispersion of the pixel values of the pixels among theplurality of blocks.

Further, according to the present disclosure, there is provided aninformation processing method executed by a computer. The informationprocessing method includes specifying, from among a plurality of blocksthat are set by dividing pixels included in at least a partial region ofa pixel region having a plurality of pixels arrayed therein and each ofwhich includes at least one or more of the pixels, at least one or moreof the blocks, and generating a unique value based on pixel values ofthe pixels included in the specified blocks and a dispersion of thepixel values of the pixels among the plurality of blocks.

Furthermore, according to the present disclosure, there is provided arecording medium on which a program is recorded, the program causing acomputer to execute specifying, from among a plurality of blocks thatare set by dividing pixels included in at least a partial region of apixel region having a plurality of pixels arrayed therein and each ofwhich includes at least one or more of the pixels, at least one or moreof the blocks, and generating a unique value based on pixel values ofthe pixels included in the specified blocks and a dispersion of thepixel values of the pixels among the plurality of blocks.

Advantageous Effects of Invention

As described above, according to the present disclosure, an informationprocessing apparatus, an information processing method, and a recordingmedium that can generate a value unique to a solid-state imagingapparatus utilizing a physical feature of the solid-state imagingapparatus are provided.

It is to be noted that the advantageous effect described above is notnecessarily restrictive and some advantageous effects indicated in thepresent specification or other advantageous effects that can be graspedfrom the present specification may be demonstrated in place of theadvantageous effect described above.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic block diagram depicting an example of aconfiguration of a solid-state imaging apparatus according an embodimentof the present disclosure.

FIG. 2 is a view depicting an outline of a configuration example of astacked type solid-state imaging apparatus to which a technologyaccording to the present disclosure can be applied.

FIG. 3 is a sectional view depicting a first configuration example of astacked type solid-state imaging apparatus 23020.

FIG. 4 is a sectional view depicting a second configuration example ofthe stacked type solid-state imaging apparatus 23020.

FIG. 5 is a sectional view depicting a third configuration example ofthe stacked type solid-state imaging apparatus 23020.

FIG. 6 is a view depicting a different configuration example of astacked type solid-state imaging apparatus to which the technologyaccording to the present disclosure can be applied.

FIG. 7 is a block diagram depicting an example of a functionalconfiguration of part of the solid-state imaging apparatus according tothe embodiment of the present disclosure.

FIG. 8 is a view depicting an example of a circuit configuration of aunit pixel according to the embodiment of the present disclosure.

FIG. 9 is an explanatory view depicting a functional configurationexample of a solid-state imaging device according to a first embodimentof the present disclosure.

FIG. 10A is an explanatory view depicting a circuit configurationexample of a clip circuit in the first embodiment.

FIG. 10B is an explanatory view depicting a circuit configurationexample of a reference signal generation section, a current source and acomparator in the first embodiment.

FIG. 11A is an explanatory view depicting, in a timing chart, operationwhen unique information relating to the first embodiment is generated.

FIG. 11B is an explanatory view depicting, in a timing chart, operationwhen unique information relating to the first embodiment is generated.

FIG. 11C is an explanatory view depicting, in a timing chart, operationwhen unique information relating to the first embodiment is generated.

FIG. 11D is an explanatory view depicting, in a timing chart, operationwhen unique information relating to the first embodiment is generated.

FIG. 11E is an explanatory view depicting, in a timing chart, operationwhen unique information relating to the first embodiment is generated.

FIG. 11F is an explanatory view depicting, in a timing chart, operationwhen unique information relating to the first embodiment is generated.

FIG. 11G is an explanatory view depicting, in a timing chart, operationwhen unique information relating to the first embodiment is generated.

FIG. 11H is an explanatory view depicting, in a timing chart, operationwhen unique information relating to the first embodiment is generated.

FIG. 12 is an explanatory view depicting a functional configurationexample of the solid-state imaging device according to the firstembodiment.

FIG. 13 is a flow chart depicting an operation example of thesolid-state imaging device according to the first embodiment.

FIG. 14 is an explanatory view illustrating an example of a technologyrelating to generation of a PUF value according to a second embodimentof the present disclosure.

FIG. 15 is an explanatory view illustrating an example of a technologyrelating to generation of a PUF value relating to the second embodiment.

FIG. 16 is an explanatory view illustrating an example of the technologyrelating to generation of a PUF value relating to the second embodiment.

FIG. 17 is an explanatory view illustrating an example of a generationmethod of a PUF value relating to the second embodiment.

FIG. 18 is an explanatory view illustrating an example of the generationmethod of a PUF value relating to the second embodiment.

FIG. 19 is a block diagram depicting an example of a functionalconfiguration of a solid-state imaging apparatus according to the secondembodiment.

FIG. 20 is a flow chart depicting an example of a flow of a series ofprocesses of the solid-state imaging apparatus according to the secondembodiment.

FIG. 21 is a flow chart depicting an example of a flow of a series ofprocesses of the solid-state imaging apparatus 1 according to the secondembodiment.

FIG. 22 is a block diagram depicting an example of a schematicfunctional configuration of an imaging apparatus in the case where it isapplied to biometric authentication.

FIG. 23 is a block diagram depicting another example of the schematicfunctional configuration of the imaging apparatus in the case where itis applied to biometric authentication.

FIG. 24 is a block diagram depicting a further example of the schematicfunctional configuration of the imaging apparatus in the case where itis applied to biometric authentication.

FIG. 25 is a block diagram depicting an example of a schematic systemconfiguration of a biometric authentication system.

FIG. 26 is a block diagram depicting an example of a schematicfunctional configuration of an imaging apparatus that configures abiometric authentication system.

FIG. 27 is a block diagram depicting an example of a schematicfunctional configuration of a server that configures a biometricauthentication system.

FIG. 28 is a block diagram depicting an example of schematicconfiguration of a vehicle control system.

FIG. 29 is a diagram of assistance in explaining an example ofinstallation positions of an outside-vehicle information detectingsection and an imaging section.

DESCRIPTION OF EMBODIMENTS

In the following, preferred embodiments of the present disclosure aredescribed in detail with reference to the accompanying drawings. It isto be noted that, in the present specification and the drawings,components having substantially the same functional configurations aredenoted by the same reference signs and overlapping description of themis omitted.

It is to be noted that the description is given in the following order.

-   -   1. Configuration Example of Solid-State Imaging Apparatus        -   1.1. General Configuration        -   1.2. Functional Configuration        -   1.3. Circuit Configuration of Unit Pixel    -   2. Outline of PUF    -   3. First Embodiment        -   3.1. Configuration Example        -   3.2. Operation Example    -   4. Second Embodiment        -   4.1. Basic Idea        -   4.2. Generation Method of PUF Value        -   4.3. Functional Configuration        -   4.4. Processing        -   4.5. Evaluation    -   5. Application Example        -   5.1. Application Example to Biometric Authentication        -   5.2. Application Example to Biometric Authentication System        -   5.3. Application Example to Mobile Body    -   6. Conclusion

1. Configuration Example of Solid-State Imaging Apparatus

A configuration example of a solid-state imaging apparatus according tothe present embodiment is described in the following.

1.1. General Configuration

FIG. 1 depicts a general configuration of a CMOS solid-state imagingapparatus as an example of a configuration of a solid-state imagingapparatus according to an embodiment of the present disclosure. ThisCMOS solid-state imaging apparatus is applied to a solid-state imagingapparatus of each embodiment. The solid-state imaging apparatus 1 of thepresent example includes, as depicted in FIG. 1, a pixel array(so-called pixel region) 3 in which a plurality of pixels 2 eachincluding a photoelectric conversion section are regularly arrayed in atwo-dimensional array on a semiconductor substrate 11, for example, asilicon substrate, and a peripheral circuit section. Each pixel 2includes, for example, a photodiode serving as the photoelectricconversion section, and a plurality of pixel transistors (so-called MOStransistors). The plurality of pixel transistors can include, forexample, three transistors of a transfer transistor, a reset transistorand an amplification transistor. Also, the plurality of pixeltransistors can otherwise include four transistors additionallyincluding a selection transistor. It is to be noted that an example ofan equivalent circuit of a unit pixel is hereinafter describedseparately. The pixel 2 can be configured as a single unit pixel. Alsoit is possible for the pixel 2 to have a shared pixel structure. Thisshared pixel structure includes a plurality of photodiodes, a pluralityof transfer transistors, a single shared floating diffusion, and otherpixel transistors shared one by one. In particular, a shared pixel isconfigured such that photodiodes and transfer transistors that configurea plurality of unit pixels share one by one of the other pixeltransistors.

The peripheral circuit section includes a vertical driving circuit 4,column signal processing circuits 5, a horizontal driving circuit 6, anoutputting circuit 7, a control circuit 8 and so forth.

The control circuit 8 receives an input clock and data that designatesan operation mode and so forth and outputs data of internal informationand so forth of the solid-state imaging apparatus. In particular, thecontrol circuit 8 generates a clock signal that becomes a reference tooperation of the vertical driving circuit 4, the column signalprocessing circuits 5, the horizontal driving circuit 6 and so forth anda control signal on the basis of a vertical synchronizing signal, ahorizontal synchronizing signal and a master clock. Then, the controlcircuit 8 inputs the signals to the vertical driving circuit 4, thecolumn signal processing circuits 5, the horizontal driving circuit 6and so forth.

The vertical driving circuit 4 includes, for example, a shift register,and selects a pixel driving wiring line and supplies a pulse for drivinga pixel to the selected pixel driving wiring line to drive pixels in aunit of a row. In particular, the vertical driving circuit 4 selectivelyscans the pixels 2 of the pixel array 3 in a unit of a row successivelyin a vertical direction and supplies pixel signals based on signalcharge generated in response to a received light amount, for example, atthe photodiode that serves as a photoelectric conversion section of eachof the pixels 2 through a vertical signal line 9 to the correspondingcolumn signal processing circuit 5.

The column signal processing circuit 5 is disposed, for example, foreach column of the pixels 2 and performs signal processing of signalsoutputted from the pixels 2 for one row such as noise removal for eachpixel column. In particular, the column signal processing circuit 5performs signal processing such as CDS for removing fixed pattern noiseunique to the pixels 2, signal amplification, AD conversion and soforth. A horizontal selection switch (not depicted) is provided at anoutput stage of the column signal processing circuit 5 such that it isconnected between the column signal processing circuit 5 and ahorizontal signal line 10.

The horizontal driving circuit 6 includes, for example, a shiftregister, and sequentially outputs a horizontal scanning pulse to selecteach of the column signal processing circuits 5 in order such that apixel signal is outputted from each of the column signal processingcircuits 5 to the horizontal signal line 10.

The outputting circuit 7 performs signal processing for each of signalssuccessively supplied from the column signal processing circuits 5through the horizontal signal line 10 and outputs a resulting signal.For example, only buffering may be performed, or black level adjustment,column dispersion correction, various digital signal processes and soforth may be performed. Input/output terminals 12 transfer a signal toand from the outside.

FIG. 2 is a view depicting an outline of a configuration example of astacked type solid-state imaging apparatus to which the technologyaccording to the present disclosure can be applied.

A of FIG. 2 depicts a schematic configuration example of a non-stackedtype solid-state imaging apparatus. The solid-state imaging apparatus23010 includes a single die (semiconductor substrate) 23011 as depictedin A of FIG. 2. In the die 23011, a pixel region 23012 in which pixelsare disposed in an array, a control circuit 23013 that performs drivingand various other controls for the pixels, and a logic circuit 23014 forperforming signal processing.

B and C of FIG. 2 depict schematic configuration examples of a stackedtype solid-state imaging apparatus. The solid-state imaging apparatus23020 is configured as one semiconductor chip in which two dies of asensor die 23021 and a logic die 23024 are stacked and electricallyconnected to each other as depicted in B and C of FIG. 2.

In B of FIG. 2, the pixel region 23012 and the control circuit 23013 areincorporated in the sensor die 23021, and the logic circuit 23014including a signal processing circuit that performs signal processing isincorporated in the logic die 23024.

In C of FIG. 2, the pixel region 23012 is incorporated in the sensor die23021, and the control circuit 23013 and a logic circuit 23014 areincorporated in the logic die 23024.

FIG. 3 is a sectional view depicting a first configuration example ofthe stacked type solid-state imaging apparatus 23020.

In the sensor die 23021, a PD (photodiode), an FD (floating diffusion),and a Tr (MOS FET) that configure the pixels that form the pixel region23012 and a Tr and so forth that form the control circuit 23013 areformed. Further, in the sensor die 23021, a wiring line layer 23101having a plurality of layers, three layers in the present example, ofwiring lines 23110, is formed. It is to be noted that (the Tr thatforms) the control circuit 23013 can be configured not in the sensor die23021 but in the logic die 23024.

In the logic die 23024, a Tr configuring the logic circuit 23014 isformed. Further, a wiring line layer 23161 having a plurality of layers,three layers in the present example, of wiring lines 23170 is formed inthe logic die 23024. Further, in the logic die 23024, a connection hole23171 having an insulating film 23172 formed on an inner wall facethereof is formed, and a connection conductor 23173 connected to awiring line 23170 and so forth is embedded in the connection hole 23171.

The sensor die 23021 and the logic die 23024 are pasted to each othersuch that the wiring line layers 23101 and 23161 face each other therebyto configure the stacked type solid-state imaging apparatus 23020 inwhich the sensor die 23021 and the logic die 23024 are stacked. On thefaces at which the sensor die 23021 and the logic die 23024 are pastedto each other, a film 23191 such as a protective film and so forth isformed.

In the sensor die 23021, a connection hole 23111 is formed such that itextends through the sensor die 23021 from the rear face side of thesensor die 23021 (side on which light is incident to the PD) (upperside) to the wiring line 23170 of the uppermost layer of the logic die23024. Further, in the sensor die 23021, a connection hole 23121 isformed in the proximity of the connection hole 23111 such that itextends from the rear face side of the sensor die 23021 to a wiring line23110 of the first layer. On an inner wall face of the connection hole23111, an insulating film 23112 is formed, and on an inner wall face ofthe connection hole 23121, an insulating film 23122 is formed. Further,connection conductors 23113 and 23123 are embedded in the connectionholes 23111 and 23121, respectively. The connection conductor 23113 andthe connection conductor 23123 are electrically connected to each otheron the rear face side of the sensor die 23021, and consequently, thesensor die 23021 and the logic die 23024 are electrically connected toeach other through the wiring line layer 23101, the connection hole23121, the connection hole 23111 and the wiring line layer 23161.

FIG. 4 is a sectional view depicting a second configuration example ofthe stacked type solid-state imaging apparatus 23020.

In the second configuration example of the solid-state imaging apparatus23020, ((the wiring line 23110 of) the wiring line layer 23101 of) thesensor die 23021 and ((the wiring line 23170 of) the wiring line layer23161 of) the logic die 23024 are electrically connected to each otherthrough a single connection hole 23211 formed in the sensor die 23021.

In particular, in FIG. 4, the connection hole 23211 is formed such thatit extends from the rear face side of the sensor die 23021 to the wiringline 23170 of the uppermost layer of the logic die 23024 through thesensor die 23021 and besides extends to the wiring line 23110 of theuppermost layer of the sensor die 23021. On an inner wall face of theconnection hole 23211, an insulating film 23212 is formed, and in theconnection hole 23211, a connection conductor 23213 is embedded.Although, in FIG. 3 described above, the sensor die 23021 and the logicdie 23024 are electrically connected to each other through the twoconnection holes 23111 and 23121, in FIG. 4, the sensor die 23021 andthe logic die 23024 are electrically connected to each other through thesingle connection hole 23211.

FIG. 5 is a sectional view depicting a third configuration example ofthe stacked type solid-state imaging apparatus 23020.

The solid-state imaging apparatus 23020 of FIG. 5 is different from thatin the case of FIG. 3, in which the film 23191 such as a protective filmis formed on the faces at which the sensor die 23021 and the logic die23024 are pasted to each other, in that the film 23191 such as aprotective film is not formed on the faces at which the sensor die 23021and the logic die 23024 are pasted to each other.

The solid-state imaging apparatus 23020 of FIG. 5 is configured byplacing the sensor die 23021 and the logic die 23024 one on the othersuch that the wiring lines 23110 and 23170 contact directly with eachother and heating them while a required load is applied to them todirectly join the wiring lines 23110 and 23170 to each other.

FIG. 6 is a sectional view depicting a different configuration exampleof a stacked type solid-state imaging apparatus to which the technologyaccording to the present disclosure can be applied.

In FIG. 6, a solid-state imaging apparatus 23401 has a stacked structureof three layers in which three dies of a sensor die 23411, a logic die23412 and a memory die 23413 are stacked.

The memory die 23413 includes a memory circuit that stores data to betemporarily required, for example, in signal processing performed by thelogic die 23412.

Although, in FIG. 6, the logic die 23412 and the memory die 23413 arestacked in this order under the sensor die 23411, also it is possible tostack the logic die 23412 and the memory die 23413 in the reverse order,namely, in the order of the memory die 23413 and the logic die 23412,under the sensor die 23411.

It is to be noted that, in FIG. 6, in the sensor die 23411, a PD servingas a photoelectric conversion section of a pixel and a source/drainregion of a pixel Tr are formed.

A gate electrode is formed around the PD with a gate insulating filminterposed therebetween, and a pixel Tr 23421 and a pixel Tr 23422 eachinclude the gate electrode and the source/drain regions paired with eachother.

The pixel Tr 23421 neighboring with the PD is a transfer Tr, and one ofthe paired source/drain regions configuring the pixel Tr 23421 serves asan FD.

Further, in the sensor die 23411, an interlayer insulating film isformed, and a connection hole is formed in the interlayer insulatingfilm. In the connection hole, a connection conductor 23431 connecting tothe pixel Tr 23421 and the pixel Tr 23422 is formed.

Furthermore, in the sensor die 23411, a wiring line layer 23433 having aplurality of layers of wiring lines 23432 connecting to the respectiveconnection conductors 23431 is formed.

Further, an aluminum pad 23434 serving as an electrode for externalconnection is formed in the lowermost layer of the wiring line layer23433 of the sensor die 23411. In particular, in the sensor die 23411,the aluminum pad 23434 is formed at a position nearer to an adhesionface 23440 to the logic die 23412 than the wiring line 23432. Thealuminum pad 23434 is used as one end of a wiring line for inputting andoutputting of a signal from and to the outside.

Furthermore, on the sensor die 23411, a contact 23441 that is used forelectric connection to the logic die 23412 is formed. The contact 23441is connected to a contact 23451 of the logic die 23412 and is connectedalso to an aluminum pad 23442 of the sensor die 23411.

Further, on the sensor die 23411, a pad hole 23443 is formed such thatit extends from the rear face side (upper side) of the sensor die 23411to the aluminum pad 23442.

The technology according to the present disclosure can be applied tosuch a solid-state imaging apparatus as described above.

It is to be noted that, in the examples described with reference toFIGS. 3 to 6, for example, a copper (Cu) wiring line is used for thevarious wiring lines. Further, in the following description, aconfiguration in which wiring lines (for example, the wiring lines 23110and 23170 depicted in FIG. 5) are directly joined to each other betweensensor dies stacked with each other as depicted in FIG. 5 is referred toalso as “Cu—Cu joining.”

1.2. Functional Configuration

Now, an example of a functional configuration of the solid-state imagingapparatus according to the embodiment of the present disclosure isdescribed with reference to FIG. 7. FIG. 7 is a block diagram depictingan example of a functional configuration of part of the solid-stateimaging apparatus according to the embodiment of the present disclosure.The solid-state imaging apparatus 1 depicted in FIG. 7 is an imagingdevice that images an imaging object to obtain digital data of acaptured image such as, for example, a CMOS (Complementary Metal OxideSemiconductor) image sensor or a CCD (Charge Coupled Device) imagesensor.

As depicted in FIG. 7, the solid-state imaging apparatus 1 includes acontrol section 101, a pixel array section 111, a selection section 112,an A/D conversion section (ADC (Analog Digital Converter)) 113 and afixed current circuit section 114.

The control section 101 controls the components of the solid-stateimaging apparatus 1 and causes the components to execute processesrelating to reading out and so forth of image data (pixel signal).

The pixel array section 111 is a pixel region in which pixelconfigurations including a photoelectric conversion element such as aphotodiode are arrayed in a matrix (array). The pixel array section 111is controlled by the control section 101 to cause the pixels to receivelight of an imaging object, photoelectrically convert the incident lightto accumulate charge, and output the charge accumulated in the pixels asa pixel signal at a predetermined timing.

A pixel 121 and another pixel 122 indicate two pixels neighboringupwardly and downwardly with each other within the pixel group disposedin the pixel array section 111. The pixel 121 and the pixel 122 arepixels in successive rows in a same column with each other. In the caseof the example of FIG. 7, as indicated by the pixel 121 and the pixel122, a photoelectric conversion element and four transistors are usedfor the circuit of each pixel. It is to be noted that the configurationof the circuit of each pixel is arbitrary and may be different from theexample depicted in FIG. 7.

In a general pixel array, an output line for a pixel signal is providedfor each column. In the case of the pixel array section 111, two (twosystems) of output lines are provided for each one column. The circuitsof pixels in one column are connected alternately to the two outputlines at every other row. For example, the circuits of the pixels inodd-numbered rows from above are connected to one of the output lineswhile the circuits of the pixels in even-numbered rows are connected tothe other one of the output lines. Although, in the case of the exampleof FIG. 7, the circuit of the pixel 121 is connected to a first outputline (VSL1) and the circuit of the pixel 122 is connected to a secondoutput line (VSL2).

It is to be noted that, although, in FIG. 7, output lines only for onecolumn are depicted for the convenience of description, actually twooutput lines are provided for each column. To each output line, thecircuits of pixels in the column are connected at every other row.

The selection section 112 includes a switch for connecting each outputline of the pixel array section 111 to an input of the ADC 113 andcontrols the connection between the pixel array section 111 and the ADC113 under the control of the control section 101. In short, a pixelsignal read out from the pixel array section 111 is supplied to the ADC113 through the selection section 112.

The selection section 112 includes a switch 131, another switch 132 anda further switch 133. The switch 131 (selection SW) controls theconnection of the two output lines corresponding to the same column. Forexample, if the switch 131 is placed into an ON state, then the firstoutput line (VSL1) and the second output line (VSL2) are connected toeach other, but if the switch 131 is placed into an OFF state, they aredisconnected from each other.

Although details are hereinafter described, in the solid-state imagingapparatus 1, one ADC is provided for each of the output lines (columnADC). Accordingly, if it is assumed that the switch 132 and the switch133 are both in an ON state, then if the switch 131 is placed into an ONstate, then the two output lines in the same column are connected toeach other, and therefore, the circuit of one pixel is connected to thetwo ADCs. By contrast, if the switch 131 is placed into an OFF state,then the two output lines of the same column are disconnected from eachother, and therefore, the circuit of one pixel is connected to one ADC.In short, the switch 131 selects the number of ADCs (column ADCs) to bemade an outputting destination of a signal of one pixel.

Although details are hereinafter described, by controlling the number ofADCs to be made an outputting destination of a pixel signal by theswitch 131 in this manner, the solid-state imaging apparatus 1 canoutput more various pixel signals in response to the number of suchADCs. In short, the solid-state imaging apparatus 1 can implement morevarious data outputting.

The switch 132 controls the connection between the first output line(VSL1) corresponding to the pixel 121 and the ADC corresponding to theoutput line. If the switch 132 is placed into an ON state, then thefirst output line is connected to one of the inputs of a comparator ofthe corresponding ADC. On the other hand, if the switch 132 is placedinto an OFF state, then the connection between them is cancelled.

The switch 133 controls the connection between the second output line(VSL2) corresponding to the pixel 122 and the ADC corresponding to theoutput line. If the switch 133 is placed into an ON state, then thesecond output line is connected to one of the inputs of the comparatorof the corresponding ADC. On the other hand, if the switch 133 is placedinto an OFF state, then the connection between them is cancelled.

The selection section 112 can control the number of ADCs (column ADCs)to be made an outputting destination of a signal of one pixel byswitching the state of such switch 131 to switch 133 as described aboveunder the control of the control section 101.

It is to be noted that the switch 132 and/or the switch 133 (one or bothof them) may be omitted such that each output line and an ADCcorresponding to the output line are normally connected. However, bymaking it possible to control connection/disconnection of them using theswitches described above, the width of selection of the number of ADCs(column ADCs) to be made an outputting destination of a signal of onepixel is expanded. In short, by providing the switches described above,the solid-state imaging apparatus 1 can output more various pixelsignals.

It is to be noted that, although FIG. 7 depicts only a configuration ofoutput lines for one column, actually the selection section 112 has aconfiguration (switch 131 to switch 133) similar to that depicted inFIG. 7 for each column. In short, the selection section 112 performsconnection control similar to that described above for each column underthe control of the control section 101.

The ADC 113 A/D converts a pixel signal supplied through each outputline from the pixel array section 111 and outputs the resulting signalas digital data. The ADC 113 includes an ADC (column ADC) for eachoutput line from the pixel array section 111. In short, the ADC 113includes a plurality of column ADCs. A column ADC corresponding to oneoutput line is a single slope type ADC including a comparator, a D/Aconverter (DAC) and a counter.

The comparator compares the DAC output and a signal value of a pixelsignal with each other. The counter increments its count value (digitalvalue) until the pixel signal and the DAC output become equal to eachother. If the DAC output reaches the signal value, then the comparatorstops the counter. Thereafter, signals digitalized by the counters 1 and2 are outputted to the outside of the solid-state imaging apparatus 1from DATA1 and DATA2.

The counter returns the count value to its initial value (for example,0) after the data outputting in order to prepare for next A/Dconversion.

The ADC 113 includes two systems of column ADCs for each column. Forexample, for the first output line (VSL1), a comparator 141 (COMP1), aDAC 142 (DAC1) and a counter 143 (counter 1) are provided and, for thesecond output line (VSL2), a comparator 151 (COMP2), a DAC 152 (DAC2)and a counter 153 (counter 2) are provided. Though not depicted, the ADC113 has a similar configuration also for output lines of the othercolumns.

However, among the components, the DACs can be commonized. Suchcommonality of the DACs is performed for each system. In other words,the DACs of the systems same as each other in the columns arecommonized. In the case of the example of FIG. 7, the DACs correspondingto the first output lines (VSL1) of the columns are commonized as theDAC 142, and the DACs corresponding to the second output lines (VSL2) ofthe columns are commonized as the DAC 152. It is to be noted that thecomparator and the counter are provided for each system of each outputline.

The fixed current circuit section 114 is a fixed current circuitconnected to each output line and is controlled and driven by thecontrol section 101. The circuit of the fixed current circuit section114 includes, for example, MOS (Metal Oxide Semiconductor) transistorsand so forth. Although this circuit configuration is arbitrary, in FIG.7, an MOS transistor 161 (LOAD1) is provided on the first output line(VSL1) and an MOS transistor 162 (LOAD2) is provided on the secondoutput line (VSL2).

The control section 101 accepts a request from the outside such as, forexample, a user and selects a reading out mode, and controls theselection section 112 to control connection to the output lines.Further, the control section 101 controls, for example, driving of acolumn ADC in response to the selected reading out mode. Furthermore,the control section 101 controls, in addition to the column ADC, drivingof the fixed current circuit section 114 as occasion demands or controlsdriving of the pixel array section 111 in regard to, for example, areading out rate, timing and so forth.

In short, the control section 101 can perform not only control of theselection section 112 but can cause the components other than theselection section 112 to operate in more various modes. Accordingly, thesolid-state imaging apparatus 1 can output more various pixel signals.

It is to be noted that the number of each of the components depicted inFIG. 7 is arbitrary if not insufficient. For example, for each column,three or more systems of output lines may be provided. Further, thenumber of pixel signals to be outputted in parallel to the outside maybe increased by increasing the number of parallel pixel signals to beoutputted from the ADC 132 or the number of the ADCs 132 themselvesdepicted in FIG. 7.

An example of the functional configuration of the solid-state imagingapparatus according to the one embodiment of the present disclosure isdescribed above with reference to FIG. 7.

1.3. Circuit Configuration of Unit Pixel

Subsequently, an example of a circuit configuration of a unit pixel isdescribed with reference to FIG. 8. FIG. 8 is a view depicting anexample of a circuit configuration of a unit pixel according to anembodiment of the present disclosure. As depicted in FIG. 8, the unitpixel 121 according to the embodiment of the present disclosure includesa photoelectric conversion section, for example, a photodiode PD, andfour pixel transistors. The four pixel transistors are, for example, atransfer transistor Tr11, a reset transistor Tr12, an amplificationtransistor Tr13 and a selection transistor Tr14. The pixel transistorscan include, for example, n-channel MOS transistors.

The transfer transistor Tr11 is connected between the cathode of thephotodiode PD and a floating diffusion section FD. Signal charge (here,electrons) obtained by photoelectric conversion by and accumulated inthe photodiode PD is transferred to the floating diffusion section FD byapplication of a transfer pulse φTRG to the gate of the photodiode PD.It is to be noted that reference sign Cfd schematically depicts aparasitic capacitance of the floating diffusion section FD.

The reset transistor Tr12 is connected at the drain thereof to a powersupply VDD and at the source thereof to the floating diffusion sectionFD. Prior to transfer of signal charge from the photodiode PD to thefloating diffusion section FD, the potential of the floating diffusionsection FD is reset by application of a reset pulse φRST to the gate ofthe reset transistor Tr12.

The amplification transistor Tr13 is connected at the gate thereof tothe floating diffusion section FD, at the drain thereof to the powersupply VDD and at the source thereof to the drain of the selectiontransistor Tr14. The amplification transistor Tr13 outputs the potentialof the floating diffusion section FD after reset by the reset transistorTr12 as a reset level to the selection transistor Tr14. Further, theamplification transistor Tr13 outputs the potential of the floatingdiffusion section FD after signal charge is transferred by the transfertransistor Tr11 as a signal level to the selection transistor Tr14.

The selection transistor Tr14 is connected, for example, at the drainthereof to the source of the amplification transistor Tr13 and at thesource thereof to the vertical signal line 9. The selection transistorTr14 is placed into an ON state by a selection pulse φSEL applied to thegate thereof and outputs a signal outputted from the amplificationtransistor Tr13 to the vertical signal line 9. It is to be noted thatalso it is possible to adopt such a configuration that the selectiontransistor Tr14 is connected between the power supply VDD and the drainof the amplification transistor Tr13.

It is to be noted that, in the case where the solid-state imagingapparatus 1 according to the present embodiment is configured as astacked type solid-state imaging apparatus, for example, such elementsas a photodiode and a plurality of MOS transistors are formed in thesensor die 23021 in B or C of FIG. 2. Further, a transfer pulse, a resetpulse, a selection pulse and a power supply voltage are supplied fromthe logic die 23024 in B or C of FIG. 2. Further, elements at succeedingstages to the vertical signal line 9 connected to the drain of theselection transistor, elements at succeeding stages to the verticalsignal line 9 connected to the drain of the selection transistor, areconfigured in the logic circuit 23014 and formed in the logic die 23024.

The example of the circuit configuration of a unit pixel is describedabove with reference to FIG. 8.

2. Outline of PUF

Now, an outline of the PUF (Physically Unclonable Function) isdescribed. The PUF is a function of outputting a unique value to adevice utilizing a physical feature difficult to duplicate. As anexample of the PUF, an Arbiter PUF, an SRAM PUB, a Glitch PUF and soforth are listed.

For example, the Arbiter PUF is a technology of utilizing a delaydifference between signals arriving at a circuit called Arbiter throughtwo routes to output a value unique to the device. Meanwhile, the SRAMPUF is a technology of utilizing a difference between initial valuesimmediately after the power supply is turned on to an SRAM (StaticRandom Access Memory) to output a value unique to the device. Further,the Glitch PUF is a technology of utilizing a phenomenon called Glitchthat occurs from a delay relation between input and output signals ofeach of gates configuring a logic circuit to output a value unique tothe device.

A value unique to a device generated utilizing such a PUF as describedabove is expected to be utilized, from its characteristic that it isdifficult to duplicate, for example, as an identifier (ID) foridentifying an individual device or as so-called key information (forexample, a key in encryption).

An outline of the PUF is described above. It is to be noted that, in thedescription given below, a value unique to a device generated using thePUF described above is referred to also as “PUF value.”

3. First Embodiment

As a first embodiment, a solid-state imaging device that internallycompletes an encryption process is described. A technology forgenerating a cryptographic key in the inside of an imaging apparatus onthe basis of unique information unique to a solid-state imaging deviceis conventionally available. However, if unique information is outputtedfrom a solid-state imaging device and is encrypted by a function blockdifferent from the solid-state imaging device, then there is thepossibility that the unique information used in the encryption may leak.

Therefore, the first embodiment described below is directed to asolid-state imaging device that completes an encryption process in theinside thereof using unique information without outputting the uniqueinformation to the outside.

3.1. Configuration Example

FIG. 9 is an explanatory view depicting a functional configurationexample of a solid-state imaging device according to the firstembodiment of the present disclosure. What is depicted in FIG. 9 is afunctional configuration example of a solid-state imaging apparatus 1that completes an encryption process using unique information in theinside thereof. In the following, the functional configuration exampleof the solid-state imaging device according to the first embodiment ofthe present disclosure is described with reference to FIG. 9.

As depicted in FIG. 9, the solid-state imaging apparatus 1 according tothe first embodiment of the present disclosure includes a drivingcontrolling section 210, a pixel array section 211 having predeterminedrows and columns and including an imaging section 212 and a uniqueinformation generation section 214, a clip circuit 215, a referencesignal generation section 216, a current source 217, a detection section218, a unique value calculation section 220, an encryption section 222and a communication controlling section 224.

The driving controlling section 210 generates a signal for driving theimaging section 212 or the unique information generation section 214hereinafter described on the basis of a predetermined input clock anddata to drive the imaging section 212 or the unique informationgeneration section 214. The driving controlling section 210 may include,for example, the control circuit 8, the vertical driving circuit 4 andthe horizontal driving circuit 6 in the configuration of the solid-stateimaging apparatus 1 described hereinabove with reference to FIG. 1.Further, the driving controlling section 210 may be provided in thecontrol circuit 23013 depicted in FIG. 2.

The driving controlling section 210 may have a function for switching,when it drives the pixel array section 211, between driving of theimaging section 212 and driving of the unique information generationsection 214. Where the driving controlling section 210 has the functionfor switching between driving of the imaging section 212 and driving ofthe unique information generation section 214, commonization of thecircuits of the imaging section 212 and the unique informationgeneration section 214 becomes possible. Further, since the drivingcontrolling section 210 has the function for switching between drivingof the imaging section 212 and driving of the unique informationgeneration section 214, a unique device for generating uniqueinformation is not required and a unique value becomes less likely to beanalyzed.

As an alternative, the driving controlling section 210 may have afunction for separating a device for being driven when an image is to beoutputted and a device for being driven in order to detect device uniqueinformation in the pixel array section 211. Where the drivingcontrolling section 210 has the function for separating a device forbeing driven when an image is to be outputted and a device for beingdriven in order to detect device unique information, device uniqueinformation becomes less likely to leak.

As an alternative, the driving controlling section 210 may control suchthat, upon driving for detecting device unique information, bias currentdifferent from that upon driving when an image is outputted may be usedfor driving. Where the driving controlling section 210 controls suchthat, upon driving for detecting device unique information, bias currentdifferent from that upon driving when an image is outputted is used fordriving, driving suitable to stably obtain a unique value becomespossible. In particular, for example, driving of the MOS transistor 161(LOAD1) and the MOS transistor 162 (LOAD2) in the circuit depicted inFIG. 7 can be made differ upon driving for detecting device uniqueinformation and upon driving for outputting an image. By making drivingof the MOS transistor 161 (LOAD1) and the MOS transistor 162 (LOAD2)differ, a characteristic appearing at the amplification transistor AMPcan be changed. Where the driving controlling section 210 controls suchthat driving for detecting device unique information is performed withbias current according to the temperature, driving for obtaining a morestable unique value becomes possible.

When the driving controlling section 210 performs driving for detectingdevice unique information with bias current different from that upondriving when an image is outputted, the driving controlling section 210may control such that driving is performed with bias current accordingto a chip temperature of the solid-state imaging apparatus 1.

The pixel array section 211 is configured such that unit pixels ofpredetermined rows and columns are arrayed and data is outputted by asource follower circuit.

The imaging section 212 has a pixel array in which a plurality of pixelsincluding a photoelectric conversion section are arrayed in atwo-dimensional array and is driven by the driving controlling section210 to output an analog signal. The circuit configuration of each pixelin the imaging section 212 is, for example, such as depicted in FIG. 8.

In the unique information generation section 214, for example, circuitshaving a configuration same as that of the pixels provided in theimaging section 212 are arrayed one-dimensionally and are driven by thedriving controlling section 210 to output an analog signal. The circuitformed as the unique information generation section 214 may be producedby substantially the same production steps as those of the pixelsprovided in the imaging section 212. Further, the driving controllingsection 210 may perform switching between driving of the imaging section212 and driving of the unique information generation section 214.

The unique information generation section 214 may be pixels provided inan optical black (OPB) region in the pixel array. The devices in thecircuit configured as the unique information generation section 214 havea physical dispersion upon production. In the solid-state imagingapparatus 1 according to the first embodiment of the present disclosure,unique information that cannot be duplicated (device unique information)is based on an analog signal outputted from the unique informationgeneration section 214.

An example of a generation source of an analog signal to be outputtedfrom the unique information generation section 214 is described. In thefollowing description, it is assumed that the unique informationgeneration section 214 has a configuration similar to that of the pixel121 depicted in FIG. 7 or 8.

(Photodiode PD) The photodiode PD has a noise component arising fromcrystal defect upon production. The crystal defect gives rise todispersion of dark current. The crystal defect appears as fixed patternnoise.

(Selection Transistor SEL)

The selection transistor SEL has a noise component arising from adispersion of a threshold voltage Vth. The dispersion of the thresholdvoltage Vth arises from a structural dispersion of an oxide film, achannel width, a channel length, impurities and so forth. The dispersionof the threshold voltage Vth appears as fixed pattern noise.

(Reset Transistor RST)

Also the reset transistor RST has a noise component arising from adispersion of the threshold voltage Vth. The dispersion of the thresholdvoltage Vth arises from a structural dispersion of an oxide film, achannel width, a channel length, impurities and so forth. The dispersionof the threshold voltage Vth appears as fixed pattern noise.

(Floating Diffusion Section FD)

The floating diffusion section FD has a noise component arising from acrystal defect upon production. The crystal defect gives rise to adispersion of dark current. The crystal defect appears as fixed patternnoise. When the reset transistor RST switches from ON to OFF, kTC noise(reset noise) appears at the floating diffusion section FD. This kTCnoise appears temporarily. When the reset transistor RST switches fromON to OFF, feedthrough appears at the floating diffusion section FD.This feedthrough arises from dispersion or a threshold value of theparasitic capacitance and appears as fixed pattern noise.

(Amplification Transistor AMP)

Also the amplification transistor AMP has a noise component arising froma dispersion of the threshold voltage Vth. The dispersion of thethreshold voltage Vth arises from a structural dispersion of an oxidefilm, a channel width, a channel length, impurities and so forth. Thedispersion of the threshold voltage Vth appears as fixed pattern noise.Further, the amplification transistor AMP has a noise component arisingfrom an overdrive voltage, a noise component arising from thermal noise,a noise component arising from 1/f noise and a noise component arisingfrom random telegraph noise (RTN). It is considered that the RTN arisesfrom trap-detrap of charge by a defect in an oxide film. Althoughpresence or absence of a defect in an oxide film is a unique dispersion,what is observed is a temporal signal level variation of two values ormulti-values.

Those noise components are transmitted to the detection section 218 atthe succeeding stage through a signal line (VSL). Upon ordinary driving,noise components that do not change before and after transfer of asignal from among the noise components are removed by a CDS process. Inthe present embodiment, when the solid-state imaging apparatus 1generates a unique value, it does not remove such noise components asdescribed above but uses the noise components as device uniqueinformation on which a unique value is based. By using noise componentsincluded in an analog signal outputted from the unique informationgeneration section 214 as the basis of a unique value, the solid-stateimaging apparatus 1 makes it possible to generate a unique value that isless likely to be analyzed.

The unique information generation section 214 can be provided, forexample, at a position that is not reached by light from the outside(shaded position). Since the unique information generation section 214is provided at a shaded position, the solid-state imaging apparatus 1can generate stable unique information without being influenced byambient light. Further, the unique information generation section 214may include circuits equal in number to the columns of the pixel arrayof the imaging section 212 in one or a plurality of rows. Further, theunique information generation section 214 may include a row selectionswitch that operates in accordance with a control signal from thedriving controlling section 210.

The clip circuit 215 is a circuit arrayed in n columns equal to thenumber of columns of the pixel array section 211 and is a sourcefollower circuit connected in parallel to the source follower circuit ofthe pixel array section 211. The clip circuit 215 has a function forclipping the voltage of an output line for each column (VSL voltage)such that the voltage is included in a predetermined range.

FIG. 10A is an explanatory view depicting a circuit configurationexample of the clip circuit 215. The clip circuit 215 is a sourcefollower circuit connected to a respective output lines VSL in parallelto a pixel and capable of selecting a row. The clip circuit 215 includestransistors CLPSEL and CLPAMP corresponding to the respective outputlines VSL. The transistor CLPSEL is a transistor that operates linearlyand performs control for connecting the source of the transistor CLPAMPand the output line VSL. Such control is performed with a clip selectionpulse. The transistor CLPAMP is a transistor that performs saturationoperation and outputs, if bias current is supplied thereto from acurrent source, a signal according to the input similarly to theamplification transistor AMP of the pixel. The input is given by a clipvoltage and normally is an intermediate potential of approximately 1 to2 V or the like.

In a selection state, if the output voltage of the source follower(pixel of the selected row) connected to the output line VSL becomeslower than a voltage that is outputted in response to the clip voltage,then bias current flows preferentially to the clip circuit 215. As aresult, the source follower output of the pixel of the selected rowstops its function and the voltage of the output line VSL is clipped tothe output level according to the clip voltage. Although a DC voltagecommon to the unit clip circuits for each column is supplied as the clipvoltage, at this time, the threshold value or the overdrive voltageindividually disperses similarly to the pixel source follower.

The reference signal generation section 216 averages the VSL voltagesoutputted for the individual columns from the clip circuits 215 andoutputs the averaged VSL voltage. The current source 217 is a circuitfor supplying fixed current to output a VSL voltage and is driven by acurrent controlling voltage generation section 219. The current source217 is arrayed in n columns and forms a source follower circuit togetherwith the amplification transistor in the unit pixel. The currentcontrolling voltage generation section 219 generates acurrent-controlling voltage such that the current value of the currentsource 217 does not rely upon the temperature by a band gap referencecircuit.

The detection section 218 performs signal processing for converting ananalog signal outputted from the unique information generation section214 into a digital signal. The detection section 218 includes acomparator 231, a DA converter 232 and a counter 233. The comparator 231compares a VSL voltage outputted from the current source 217 and areference waveform outputted from the DA converter 232 with each otherto convert the voltage into a time period. The comparator 231 includesan input capacitor provided on the input side and a switch that shortcircuits an input and an output of the comparator 231. The DA converter232 generates a reference waveform to be supplied to the comparator 231.The counter 233 has a function for counting until the output of thecomparator 231 is reversed to convert a time period into a count number.

The detection section 218 outputs a digital signal after conversion tothe unique value calculation section 220. The detection section 218 caninclude, in addition to the function for converting an analog signalinto a digital signal, a function for difference processing two inputsignals and a function for removing a dispersion occurring in thedetection section 218 itself. Since the detection section 218 includesthe function for removing a dispersion that occurs in the detectionsection 218 itself, a further dispersion is not provided to a signalfrom the unique information generation section 214, and therefore, thequality of a signal on which a unique value is based can be enhanced.Further, the detection section 218 may perform a column parallel processor may perform a pixel parallel process for an analog signal outputtedfrom the unique information generation section 214.

The detection section 218 may include a capacitor for clamping thepotential of a signal line and a switch for setting one end of thecapacitor to a reference potential. In particular, the detection section218 may include a switch that connects one end of a capacitive elementprovided on the input side of the comparators 141 and 151 of the ADC 113depicted in FIG. 7 and the output side of the comparators 141 and 151 toeach other. Since the one end of the capacitive element and the outputside of the comparators 141 and 151 are connected to each other by theswitch, transistors that are connected to each other by diode connectionappear among the transistors included in the comparators 141 and 151appear. This makes it possible to remove a dispersion in an analogregion because one end of the capacitor that clamps the potential of thesignal line is set to a predetermined reference potential. Further, thedetection section 218 may perform difference processing of digitalvalues after AD conversion. The detection section 218 can remove adispersion in a digital region by the difference process of digitalvalues after AD conversion.

Further, the detection section 218 may have a function for shifting theclamp level as hereinafter described. The detection section 218 canoptimize, by shifting the clamp level, the distribution of analog valuescentered at a predetermined reference upon conversion from an analogvalue into a digital value. By optimizing the distribution of analogvalues, unique information outputted from the unique informationgeneration section 214 can be obtained without any loss.

In the case where a plurality of detection sections 218 are arrayed, thedetection sections 218 may each have a function for calculating adifference between a signal inputted to the detection section 218 and areference signal common to the plurality of detection sections 218. Inthis case, the reference signal common to the plurality of detectionsections 218 may be substantially the same as an average of signalsinputted to the detection sections 218.

Between the unique information generation section 214 and the detectionsection 218, a memory for temporarily retaining unique informationoutputted from the unique information generation section 214,especially, an analog memory, may be provided. The analog memory may bea parasitic capacitance of a signal line as hereinafter described.Further, in the case where an analog memory is provided between theunique information generation section 214 and each of the plurality ofdetection sections 218, a switch for short circuiting the analogmemories may be provided. This facilitates generation of uniqueinformation, and by short circuiting the analog memories to performaveraging, the unique information retained in the individual analogmemories is erased.

FIG. 10B is an explanatory view depicting a circuit configurationexample of the reference signal generation section 216, the currentsource 217 and the comparator 231. In FIG. 10B, the (n−1)th output lineVSL(n−1), nth output line VSL(n) and (n+1)th output line VSL(n+1) aredepicted.

On the output line VSL(n−1), switches 251 a and 252 a are provided asthe reference signal generation section 216, and the output lineVSL(n−1) has a parasitic capacitance 253 a. On the output line VSL(n),switches 251 b and 252 b are provided as the reference signal generationsection 216, and the output line VSL(n) has a parasitic capacitance 253b. On the output line VSL(n+1), switches 251 c and 252 c are provided asthe reference signal generation section 216, and the output lineVSL(n+1) has a parasitic capacitance 253 c.

As the current source 217, a transistor 261 a is connected to one end ofthe switch 252 a; a transistor 261 b is connected to one end of theswitch 252 b; and a transistor 261 c is connected to one end of theswitch 252 c.

The output line VSL(n−1) has input capacitors 271 a and 272 a, switches273 a and 274 a and a comparator 275 a as the comparator 231. The outputline VSL(n) has input capacitors 271 b and 272 b, switches 273 b and 274b and a comparator 275 b as the comparator 231. The output line VSL(n+1)has input capacitors 271 c and 272 c, switches 273 c and 274 c and acomparator 275 c as the comparator 231.

FIG. 11A is an explanatory view depicting, in a timing chart, operationof the reference signal generation section 216, the current source 217and the comparator 231 when unique information is generated. In thefollowing, operation of elements provided on or along the output lineVSL(n−1) is described.

One horizontal reading out period is started at time t1. At this pointof time, the row selection signal φSEL becomes high and row selection isstarted. At this point of time, since the reset transistor RST is in anON state, the voltage of the floating diffusion section FD is fixed toVDD. Consequently, the dispersion of the floating diffusion section FDis removed. Further, when unique information is to be generated, thetransfer pulse φTRG is fixed to the low level. Since the transfer pulseφTRG is fixed to the low level, the transfer transistor TRG becomes OFF,and the dispersion of the photodiode PD can be removed.

Further, at time t1, a current source disconnection pulse fordisconnecting the current source 217 is high, and the switch 252 a isON. Further, at time t1, a VSL averaging pulse for averaging the VSLvoltage is low, and the switch 251 a is OFF. Consequently, even if asource follower operation is performed, dispersion information for eachsource follower is outputted to the output line VSL.

At time t2, the row selection signal (selection pulse) φSEL and thecurrent source disconnection pulse become the low level simultaneously,and the VSL voltage for each column is retained into the parasiticcapacitance 253 a of the VSL. Further, at time t2, the VSL averagingpulse becomes high, and the VSL voltage for each column is averaged.This averaged VSL voltage becomes a reference signal.

At the point of time of time t3, an internal offset of the comparator275 a and the difference between the VSL voltage and a referencewaveform are charged into the input capacitor 272 a, and the operatingpoint of the comparator 275 a is initialized.

At time t4, the short circuiting pulse becomes low, and the switches 273a and 274 a are turned off. Consequently, kTC noise and feedthroughdispersion at the switches 273 a and 274 a are generated.

A period from time t5 to time t6 is a first AD conversion period (ADCperiod 1). During this period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. The DA converter 232 may have a function for shifting thereference waveform. In other words, the DA converter 232 may have afunction for shifting the clamp level. The DA converter 232 can providean offset to an output of the counter 233 by shifting the referencewaveform. Further, within this ADC period 1, reversal delay of thecomparator 275 a, delay of the reference waveform and clock delay of thecounter occur. It is to be noted that what is indicated by a triangle inFIG. 11A is a reversal timing of the comparator 275 a.

When the ADC period 1 ends at time t6, the row selection signal φSELbecomes high; the current source disconnection pulse becomes high, andthe VSL averaging pulse becomes low. In particular, the switch 251 abecomes OFF and the switch 252 a becomes ON. Consequently, even if asource follower operation is performed, dispersion information for eachsource follower (dispersion of an output of the amplificationtransistor) is outputted to the output line VSL.

A period from time t7 to time t8 is a second AD conversion period (ADCperiod 2). Also during the period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Thus, thecomparator 275 a AD converts the reference signal using the referencewaveform. Here, the digital value after the conversion includes kTCnoise and feedthrough dispersion at the switches 273 a and 274 agenerated at time t4 and reversal delay of the comparator 275 a, delayof the reference waveform and clock delay of the counter occurringwithin the ADC period 1 similarly. It is to be noted that what isindicated by a triangle in FIG. 11A is a reversal timing of thecomparator 275 a.

Therefore, after the ADC period 2 ends, a difference process between thecount value of the counter 233 during the ADC period 1 and the countvalue of the counter 233 during the ADC period 2 is performed. By thisdifference process, a dispersion occurring in the detection section 218can be removed. Accordingly, a dispersion occurring in the detectionsection 218 can be prevented from being included in the device uniqueinformation.

Further, since an offset is applied to the output of the counter 233within the ADC period 1, even if the difference process is performed,the dispersion by the unique information generation section 214 is notlost. The dispersion by the unique information generation section 214indicates a normal distribution centered at the reference signal.Accordingly, if the offset is not applied, then a negative value appearswith the dispersion by the unique information generation section 214,and the values equal to or lower than 0 all become 0.

Preferably, the inclination of the reference waveform upon AD conversionis adjusted (analog gain adjustment) such that a desired digital valueis obtained. Further, upon reading out of device unique information, thecurrent of the current source (drain current Id) may be made smallerthan that upon ordinary reading out. Although the overdrive voltage canbe calculated by 2×Id/gm, since also the dispersion increases inproportion to the overdrive voltage, if the drain current Id is reduced,then the dispersion component of the overdrive voltage included in thesource follower relatively decreases. In short, information of thedispersion principally of the threshold value of the amplificationtransistor AMP can be detected. Further, upon reading out of the deviceunique information, the current of the current source (drain current Id)may be made higher than that upon ordinary reading out. By increasingthe current of the current source, also it is possible to make thedispersion component of the overdrive voltage from within the dispersioninformation included in the source follower relatively great.

Although temporal noise includes thermal noise of the amplificationtransistor AMP, 1/f noise, RTN and thermal noise of peripheral circuits,if reading out is performed by a plural number of times and results areadded (averaged), then they can be suppressed.

In order to suppress time-dependent deterioration, the solid-stateimaging apparatus 1 preferably performs driving control in accordancewith the following conditions. Taking hot carrier injection intoconsideration, preferably the current upon operation is low. In otherwords, the bias current is preferably controlled so as to become low.Similarly, taking hot carrier injection into consideration, preferablythe operating time period is short. For example, it is preferable toperform control such that driving is performed only upon activation orupon request. Similarly, taking hot carrier injection intoconsideration, it is preferable not to supply current when thesolid-state imaging apparatus 1 is not used. In particular, it ispreferable to turn off the selection transistor SEL when the solid-stateimaging apparatus 1 is not used. Further, taking destruction of an oxidefilm into consideration, when the solid-state imaging apparatus 1 is notused, the voltage difference between the gate and the source or thedrain of a target device is small. In other words, when the solid-stateimaging apparatus 1 is not used, it is preferable to turn on the resettransistor RST. Further, taking substrate hot carrier injection intoconsideration, preferably the unique information generation section 214is shielded.

Although the potential of the high level of the selection pulse φSEL maybe approximately VDD (2.7 V), it may otherwise be an intermediatepotential (approximately 1 to 1.5 V). If the potential difference (VDS)between the drain and the source of the selection transistor SEL isapplied such that saturation operation is to be performed, then a sourcefollower is formed. For example, where the drain voltage of theselection transistor SEL is 2.7 V, the voltage of the drain side of theselection transistor SEL (source side of the amplification transistorAMP) normally is approximately 2.2 V. In contrast, if VDS of theselection transistor SEL is sufficient (if there is a difference of atleast approximately several hundreds to 700 mV), then saturationoperation can be achieved. Consequently, an output according to the gatevoltage of the selection transistor SEL is transmitted to the outputline VSL. If also the selection transistor SEL is caused to performsaturation operation similarly to the amplification transistor AMP, thensince the threshold value and the overdrive voltage disperse for eachdevice, a dispersion of the threshold value and the overdrive voltage ofthe selection transistor SEL can be detected. Thereupon, the pixels andthe clip circuit 215 in a non-selected row do not participate in readingout because the selection switch is turned off.

The current controlling voltage generation section 219 can change theoverdrive voltage by driving the current controlling voltage that isdifferent between the ADC period 1 and the ADC period 2. Since thechanging amount of the overdrive voltage at this time disperses, thechanging amount of the overdrive voltage can be detected as deviceunique information.

FIG. 11B is an explanatory view depicting, in a timing chart, operationof the reference signal generation section 216, the current source 217and the comparator 231 when unique information is generated. In thefollowing, operation of elements provided on the output line VSL(n−1) oralong the output line VSL(n−1) is described. The timing chart of FIG.11B is different from the timing chart of FIG. 11A in that the currentsource disconnection pulse and the VSL averaging pulse are normally inthe low level.

One horizontal reading out period is started at time t1. At this pointof time, the row selection signal φSEL becomes high and row selection isstarted. At this point of time, since the reset transistor RST is in anON state, the voltage of the floating diffusion section FD is fixed toVDD. Consequently, the dispersion of the floating diffusion section FDis removed. Further, when unique information is generated, the transferpulse φTRG is fixed to the low level. Since the transfer pulse φTRG isfixed to the low level, the transfer transistor TRG is turned off andthe dispersion of the photodiode PD can be removed.

At the point of time of time t2, the internal offset of the comparator275 a and the difference between the VSL voltage and the referencewaveform are charged into the input capacitor 272 a, and the operatingpoint of the comparator 275 a is initialized.

At time t3, the short-circuiting pulse becomes low, and the switches 273a and 274 a are turned off. Consequently, kTC noise and feedthroughdispersion at the switches 273 a and 274 a are generated.

The period from time t4 to time t5 is a first AD conversion period (ADCperiod 1). During this period of time, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Within this ADC period 1, reversal delay of the comparator 275a, delay of the reference waveform and clock delay of the counter occur.It is to be noted that what is indicated by a triangle in FIG. 11B is areversal timing of the comparator 275 a.

Then, at the point of time of time t6, the current controlling voltagegeneration section 219 controls the current controlling voltage suchthat the bias current increases.

The period from time t7 to time t8 is a second AD conversion period (ADCperiod 2). Also during this period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Here, the digital value after the conversion similarlyincludes kTC noise and feedthrough dispersion at the switches 273 a and274 a having occurred at time t4, reversal delay of the comparator 275a, delay of the reference waveform and clock delay of the counter havingoccurred within the ADC period 1. It is to be noted that what isindicated by a triangle in FIG. 11B is a reversal timing of thecomparator 275 a.

Therefore, after the ADC period 2 ends, a difference process between thecount value of the counter 233 during the ADC period 1 and the countvalue of the counter 233 during the ADC period 2 is performed. By thisdifference process, a dispersion occurring in the detection section 218can be removed. Since only the bias current value is different betweenthe ADC period 1 and the ADC period 2, the threshold value informationis cancelled and extraction of a component of the overdrive voltagebecomes possible. Here, the gain coefficient β of the transistor is(W/L)×μ×C_(ox). W is the gate width; L the gate length; μ the mobilityof electrons; and C_(ox) the oxide film capacitance per unit area.Further, the mutual inductance gm is approximately 2^(1/2)×β×Id.Accordingly, the overdrive voltage is 2×Id/gm=(2×Id/β)^(1/2). Since βhas dispersion unique to the device, an output according to the biascurrent and the device dispersion is obtained. β includes the mobilityμ, and the mobility μ includes a temperature characteristic.Accordingly, by adjusting the bias current or the inclination of thereference waveform and the shift amount in response to the temperatureas hereinafter described, it becomes possible to moderate thecharacteristic change by the temperature and perform AD conversion in anappropriate range. Since lattice scattering is dominant at the operatingtemperature of the solid-state imaging apparatus 1, the temperaturecharacteristic of the mobility relies upon the absolute temperatureT^(−3/2).

Although, even in the case where the solid-state imaging apparatus 1operates in accordance with the timing chart depicted in FIG. 11B, thepotential of the high level of the selection pulse φSEL may beapproximately VDD (2.7 V), it may otherwise be an intermediate potential(approximately 1 to 1.5 V). If the potential difference (VDS) betweenthe drain and the source of the selection transistor SEL is applied suchthat saturation operation is performed, then a source follower isobtained.

Although the RTN is a component that varies with respect to time, adevice in which the RTN occurs is determined (FPN component).Accordingly, also detection of the RTN is possible.

Generally, the RTN occurs in a capturing or emitting process ofelectrons to a defect level and generates an output of two values ormulti values because the amplitude is great. Since the RTN usuallyincludes a temporal change, detection of the RTN is performed bycontinuous observation or by a plural number of times of sampling. Here,the temporal change indicates that the RTN has a time constant thatoriginates from the difference between the energy level the defect hasand the Fermi level of channel electrons of the amplification transistorAMP of the pixel and that a state of two values or plural values occursat an arbitrary timing.

FIG. 11C is an explanatory view depicting, in a timing chart, operationof the reference signal generation section 216, the current source 217and the comparator 231 when unique information is generated. In thefollowing, operation of elements provided on the output line VSL(n−1) oralong the output line VSL(n−1) is described.

One horizontal reading out period is started at time t1. At this pointof time, the row selection signal φSEL becomes high and row selection isstarted. At this point of time, since the reset transistor RST is in anON state, the voltage of the floating diffusion section FD is fixed toVDD. Consequently, the dispersion of the floating diffusion section FDis removed. Further, when unique information is to be generated, thetransfer pulse φTRG is fixed to the low level. Since the transfer pulseφTRG is fixed to the low level, the transfer transistor TRG is turnedoff and the dispersion of the photodiode PD can be removed.

At the point of time of time t2, the internal offset of the comparator275 a and the difference between the VSL voltage and the referencewaveform are charged into the input capacitor 272 a, and the operatingpoint of the comparator 275 a is initialized.

At time t3, the short-circuiting pulse becomes low, and the switches 273a and 274 a are turned off. Consequently, kTC noise and feedthroughdispersion at the switches 273 a and 274 a are generated.

The period from time t4 to time t5 is a first AD conversion period (ADCperiod 1). During this period of time, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Within this ADC period 1, reversal delay of the comparator 275a, delay of the reference waveform and clock delay of the counter occur.It is to be noted that what is indicated by a triangle in FIG. 11C is areversal timing of the comparator 275 a.

Then, at the point of time of time t6, the current controlling voltagegeneration section 219 controls the current controlling voltage suchthat the bias current increases.

The period from time t7 to time t8 is a second AD conversion period (ADCperiod 2). Also during this period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Here, the digital value after the conversion similarlyincludes kTC noise and feedthrough dispersion at the switches 273 a and274 a having occurred at time t4 and reversal delay of the comparator275 a, delay of the reference waveform and clock delay of the counterhaving occurred during the ADC period 1. It is to be noted that what isindicated by a triangle in FIG. 11C is a reversal timing of thecomparator 275 a.

Therefore, after the ADC period 2 ends, a difference process between thecount value of the counter 233 during the ADC period 1 and the countvalue of the counter 233 during the ADC period 2 is performed. By thisdifference process, a dispersion occurring in the detection section 218can be removed. Further, data regarding whether or not the RTN occurscan be acquired by the difference process. By performing this dataacquisition by a plural number of times, an occurrence frequency of theRTN for each of the amplification transistors AMP of the pixels can beevaluated. Accordingly, in the case where a voltage amplitude greaterthan the voltage amplitude generated by thermal noise the amplificationcircuit has or 1/f is detected, it is possible to have the address ofthe element by which the voltage amplitude can be detected as deviceunique information. In this case, in regard to the RTN, since the timeconstant changes on the basis of the energy difference as describedabove, namely, since the detection probability changes, it is desirableto have a table of addresses for each temperature.

Even in the case where the solid-state imaging apparatus 1 operates inaccordance with the timing chart depicted in FIG. 11C, the potential ofthe high level of the selection pulse φSEL may be approximately VDD (2.7V), it may otherwise be an intermediate potential (approximately 1 to1.5 V). If the potential difference (VDS) between the drain and thesource of the selection transistor SEL is applied such that saturationoperation is performed, then a source follower is obtained.

As described hereinabove, also the clip circuit 215 is a source followercircuit and can obtain device unique information by operation similar tothe operation depicted in FIG. 11A.

FIG. 11D is an explanatory view depicting, in a timing chart, operationof the clip circuit 215, the reference signal generation section 216,the current source 217 and the comparator 231 when unique information isgenerated. In the following, operation of elements provided on theoutput line VSL(n−1) or along the output line VSL(n−1) is described.

In the timing chart of FIG. 11D, the pixels are not selected in allrows. In particular, the row selection signal φSEL is fixed to the lowlevel. The state of a pulse for driving any other pixel is arbitrary.One horizontal reading out period is started at time t1. At this pointof time, the clip selection pulse φCLPSEL becomes high and the clipcircuit 215 is selected. Further, the short circuiting pulse becomes thehigh level and the switches 273 a and 274 a are connected. Since theswitch 252 a for disconnecting the current source 217 is ON and theswitch 251 a for averaging the VSL voltage is OFF, a source followeroperation is performed, and dispersion information for each sourcefollower of the clip circuit 215 (dispersion of the output of thetransistor CLPAMP) is outputted to the output line VSL.

At the point of time of time t2, the clip selection pulse φCLPSEL andthe current source disconnection pulse are made the low levelsimultaneously. Consequently, the VSL voltage is retained into theparasitic capacitance 253 a. Since averaging of the VSL voltage isperformed here, the VSL voltages of the columns are averaged. Theaveraged VSL voltage becomes a reference signal.

At the point of time of time t3, the internal offset of the comparator275 a and the difference between the VSL voltage and the referencewaveform are charged into the input capacitor 272 a, and the operatingpoint of the comparator 275 a is initialized.

At time t4, the short-circuiting pulse becomes low, and the switches 273a and 274 a are turned off. Consequently, the initialization of theoperating point of the comparator 275 a ends. Further, since theswitches 273 a and 274 a are turned off, kTC noise and feedthroughdispersion by the switches 273 a and 274 a are generated.

The period from time t5 to time t6 is a first AD conversion period (ADCperiod 1). During this period of time, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. The DA converter 232 may have a function for shifting thereference waveform. In other words, the DA converter 232 may have afunction for shifting the clamp level. The DA converter 232 can providean offset to an output of the counter 233 by shifting the referencewaveform. Within this ADC period 1, reversal delay of the comparator 275a, delay of the reference waveform and clock delay of the counter occur.It is to be noted that what is indicated by a triangle in FIG. 11D is areversal timing of the comparator 275 a.

Then, at the point of time of time t6, the clip selection pulse φCLPSELbecomes high and the clip circuit 215 is selected. At this point oftime, since the switch 252 a for disconnecting the current source 217 isON and the switch 251 a for averaging the VSL voltage is OFF, a sourcefollower operation is performed, and the dispersion information for eachsource follower of the clip circuit 215 (dispersion of the output of thetransistor CLPAMP) is outputted to the output line VSL.

The period from time t7 to time t8 is a second AD conversion period (ADCperiod 2). Also during this period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Here, the digital value after the conversion similarlyincludes kTC noise and feedthrough dispersion at the switches 273 a and274 a having occurred at time t4 and reversal delay of the comparator275 a, delay of the reference waveform and clock delay of the counterhaving occurred during the ADC period 1. It is to be noted that what isindicated by a triangle in FIG. 11D is a reversal timing of thecomparator 275 a.

Therefore, after the ADC period 2 ends, a difference process between thecount value of the counter 233 during the ADC period 1 and the countvalue of the counter 233 during the ADC period 2 is performed. By thisdifference process, a dispersion occurring in the detection section 218can be removed. Accordingly, it is possible to prevent a dispersionoccurring in the detection section 218 from being included in the deviceunique information.

Further, since an offset is applied to the output of the counter 233within the ADC period 1, even if the difference process is performed,the dispersion by the unique information generation section 214 is notlost. The dispersion by the unique information generation section 214indicates a normal distribution centered at the reference signal.Accordingly, if the offset is not applied, then a negative value appearswith the dispersion by the unique information generation section 214,and the values equal to or lower than 0 all become 0.

It is to be noted that, in the case where operation according to thetiming chart depicted in FIG. 11D is to be performed, if not thetransistor CLPAMP but the transistor CLPSEL is saturated, then a sourcefollower circuit is formed. Although the potential of the high level ofthe pulse for selecting the transistor CLPSEL may be approximately VDD(2.7 V), it may otherwise be an intermediate potential (approximately 1to 1.5 V). If the potential difference (VDS) between the drain and thesource of the transistor CLPSEL is applied such that saturationoperation is to be performed, then a source follower is formed. Forexample, where the drain voltage of the transistor CLPSEL is 2.7 V, thevoltage of the drain side of the transistor CLPSEL (source side of thetransistor CLPAMP) normally is approximately 2.2 V. In contrast, if theVDS of the transistor CLPSEL is sufficient (if there is a difference ofat least approximately several hundreds to 700 mV), then saturationoperation can be achieved. Consequently, an output according to the gatevoltage of the transistor CLPSEL is transmitted to the output line VSL.If also the transistor CLPSEL is caused to perform saturation operationsimilarly to the transistor CLPAMP, then since the threshold value andthe overdrive voltage disperse for each device, a dispersion of thethreshold value and the overdrive voltage of the transistor CLPSEL canbe detected.

The current controlling voltage generation section 219 can change theoverdrive voltage of the transistor CLPAMP by driving the currentcontrolling voltage that is different between the ADC period 1 and theADC period 2. Since the changing amount of the overdrive voltage at thistime disperses, the changing amount of the overdrive voltage can bedetected as device unique information.

FIG. 11E is an explanatory view depicting, in a timing chart, operationof the clip circuit 215, the reference signal generation section 216,the current source 217 and the comparator 231 when unique information isgenerated. In the following, operation of elements provided on theoutput line VSL(n−1) or along the output line VSL(n−1) is described. Thetiming chart of FIG. 11E is different from the timing chart of FIG. 11Din that the current source disconnection pulse and the VSL averagingpulse normally have the low level.

In the timing chart of FIG. 11E, the pixels are not selected in allrows. In particular, the row selection signal φSEL is fixed to the lowlevel. The state of a pulse for driving any other pixel is arbitrary.One horizontal reading out period is started at time t1. At this pointof time, the clip selection pulse φCLPSEL becomes high and the clipcircuit 215 is selected. Further, the short circuiting pulse becomes thehigh level and the switches 273 a and 274 a are connected.

At the point of time of time t2, the internal offset of the comparator275 a and the difference between the VSL voltage and the referencewaveform are charged into the input capacitor 272 a, and the operatingpoint of the comparator 275 a is initialized.

At time t3, the short-circuiting pulse becomes low, and the switches 273a and 274 a are turned off. Consequently, the initialization of theoperating point of the comparator 275 a ends. Further, since theswitches 273 a and 274 a are turned off, kTC noise and feedthroughdispersion by the switches 273 a and 274 a are generated.

The period from time t4 to time t5 is a first AD conversion period (ADCperiod 1). During this period of time, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Within this ADC period 1, reversal delay of the comparator 275a, delay of the reference waveform and clock delay of the counter occur.It is to be noted that what is indicated by a triangle in FIG. 11E is areversal timing of the comparator 275 a.

Then, at the point of time of time t6, the current controlling voltagegeneration section 219 controls the current controlling voltage suchthat the bias current increases.

The period from time t7 to time t8 is a second AD conversion period (ADCperiod 2). Also during this period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Here, the digital value after the conversion similarlyincludes kTC noise and feedthrough dispersion at the switches 273 a and274 a having occurred at time t4 and reversal delay of the comparator275 a, delay of the reference waveform and clock delay of the counterhaving occurred during the ADC period 1. It is to be noted that what isindicated by a triangle in FIG. 11E is a reversal timing of thecomparator 275 a.

Therefore, after the ADC period 2 ends, a difference process between thecount value of the counter 233 during the ADC period 1 and the countvalue of the counter 233 during the ADC period 2 is performed. By thisdifference process, a dispersion occurring in the detection section 218can be removed. Since only the bias current value is different betweenthe ADC period 1 and the ADC period 2, the threshold value informationis cancelled and extraction of a component of the overdrive voltagebecomes possible. Here, the gain coefficient β of the transistor is(W/L)×p×μC_(ox). W is the gate width; L the gate length; μ the mobilityof electrons; and C_(ox) the oxide film capacitance per unit area.Further, the mutual inductance gm is approximately 2^(1/2)×β×Id.Accordingly, the overdrive voltage is 2×Id/gm=(2×Id/β)^(1/2). Since βhas a dispersion unique to the device, an output according to the biascurrent and the device dispersion is obtained. β includes the mobilityμ, and the mobility μ includes a temperature characteristic.Accordingly, by adjusting the bias current or the inclination of thereference waveform and the shift amount in response to the temperatureas hereinafter described, it becomes possible to moderate thecharacteristic change by the temperature and perform AD conversion in anappropriate range. Since lattice scattering is dominant at the operatingtemperature of the solid-state imaging apparatus 1, the temperaturecharacteristic of the mobility relies upon the absolute temperatureT^(−3/2).

If, in the case where operation is performed in accordance with thetiming chart depicted in FIG. 11E, not the transistor CLPAMP but thetransistor CLPSEL is saturated, then a source follower circuit isformed. Although the potential of the high level of the pulse forselecting the transistor CLPSEL may be approximately VDD (2.7 V), it mayotherwise be an intermediate potential (approximately 1 to 1.5 V).

Also such detection of the RTN as described above is possible with thetransistor CLPAMP. When the RTN is to be detected by the transistorCLPAMP, the clip voltage is set to an intermediate potential (forexample, approximately 1.5 V to the power supply VDD).

FIG. 11F is an explanatory view depicting, in a timing chart, operationof the clip circuit 215, the reference signal generation section 216,the current source 217 and the comparator 231 when unique information isgenerated. In the following, operation of elements provided on theoutput line VSL(n−1) or along the output line VSL(n−1) is described.

In the timing chart of FIG. 11F, the pixels are not selected in allrows. In particular, the row selection signal φSEL is fixed to the lowlevel. The state of a pulse for driving any other pixel is arbitrary.One horizontal reading out period is started at time t1. At this pointof time, the clip selection pulse φCLPSEL becomes high and the clipcircuit 215 is selected. Further, the short circuiting pulse becomeshigh and the switches 273 a and 274 a are connected.

At the point of time of time t2, the internal offset of the comparator275 a and the difference between the VSL voltage and the referencewaveform are charged into the input capacitor 272 a, and the operatingpoint of the comparator 275 a is initialized.

At time t3, the short-circuiting pulse becomes low, and the switches 273a and 274 a are turned off. Consequently, the initialization of theoperating point of the comparator 275 a ends. Further, since theswitches 273 a and 274 a are turned off, kTC noise and feedthroughdispersion by the switches 273 a and 274 a are generated.

The period from time t4 to time t5 is a first AD conversion period (ADCperiod 1). During this period of time, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Within this ADC period 1, reversal delay of the comparator 275a, delay of the reference waveform and clock delay of the counter occur.It is to be noted that what is indicated by a triangle in FIG. 11F is areversal timing of the comparator 275 a.

The period from time t6 to time t7 is a second AD conversion period (ADCperiod 2). Also during this period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Here, the digital value after the conversion similarlyincludes kTC noise and feedthrough dispersion at the switches 273 a and274 a having occurred at time t4 and reversal delay of the comparator275 a, delay of the reference waveform and clock delay of the counterhaving occurred during the ADC period 1. It is to be noted that what isindicated by a triangle in FIG. 11F is a reversal timing of thecomparator 275 a.

Therefore, after the ADC period 2 ends, a difference process between thecount value of the counter 233 during the ADC period 1 and the countvalue of the counter 233 during the ADC period 2 is performed. By thisdifference process, a dispersion occurring in the detection section 218can be removed. Further, data regarding whether or not the RTN occurscan be acquired by the difference process. By performing this dataacquisition by a plural number of times, an occurrence frequency of theRTN for each of the transistors CLPAMP can be evaluated. Accordingly, inthe case where the voltage amplitude greater than a voltage amplitudegenerated by thermal noise the amplification circuit has or 1/f isdetected, it is possible to have the address of the element by which thevoltage amplitude can be detected as device unique information. In thiscase, in regard to the RTN, since the time constant changes on the basisof the energy difference as described above, that is, since thedetection probability changes, it is desirable to have a table ofaddresses for each temperature.

If, in the case where operation is performed in accordance with thetiming chart depicted in FIG. 11F, not the transistor CLPAMP but thetransistor CLPSEL is saturated, then a source follower circuit isformed. Although the potential of the high level of the pulse forselecting the transistor CLPSEL may be approximately VDD (2.7 V), it mayotherwise be an intermediate potential (approximately 1 to 1.5 V).

The solid-state imaging apparatus 1 can use a feedthrough dispersion ofthe comparator 275 a as device unique information.

FIG. 11G is an explanatory view depicting, in a timing chart, operationof the clip circuit 215, the reference signal generation section 216,the current source 217 and the comparator 231 when unique information isgenerated. In the following, operation of elements provided on theoutput line VSL(n−1) or along the output line VSL(n−1) is described.

In the timing chart of FIG. 11G, the pixels are not selected in allrows. In particular, the row selection signal φSEL is fixed to the lowlevel. The state of a pulse for driving any other pixel is arbitrary.One horizontal reading out period is started at time t1. At this pointof time, the clip selection pulse φCLPSEL becomes high and the clipcircuit 215 is selected. Further, the short circuiting pulse becomes thehigh level and the switches 273 a and 274 a are connected.

At the point of time of time t2, the internal offset of the comparator275 a and the difference between the VSL voltage and the referencewaveform are charged into the input capacitor 272 a, and the operatingpoint of the comparator 275 a is initialized.

The period from time t3 to time t4 is a first AD conversion period (ADCperiod 1). During this period of time, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Within this ADC period 1, reversal delay of the comparator 275a, delay of the reference waveform and clock delay of the counter occur.It is to be noted that what is indicated by a triangle in FIG. 11G is areversal timing of the comparator 275 a.

At time t5, the short-circuiting pulse becomes low and the switches 273a and 274 a are turned off. Consequently, the initialization of theoperating point of the comparator 275 a ends. Further, since theswitches 273 a and 274 a are turned off, kTC noise and feedthroughdispersion by the switches 273 a and 274 a are generated.

The period from time t6 to time t7 is a second AD conversion period (ADCperiod 2). Also during this period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Here, the digital value after the conversion similarlyincludes kTC noise and feedthrough dispersion at the switches 273 a and274 a having occurred at time t4 and reversal delay of the comparator275 a, delay of the reference waveform and clock delay of the counterhaving occurred during the ADC period 1. It is to be noted that what isindicated by a triangle in FIG. 11G is a reversal timing of thecomparator 275 a.

Therefore, after the ADC period 2 ends, a difference process between thecount value of the counter 233 during the ADC period 1 and the countvalue of the counter 233 during the ADC period 2 is performed. By thisdifference process, kTC noise and feedthrough dispersion at the switches273 a and 274 a are detected.

By performing detection of kTC noise and a feedthrough dispersion at theswitches 273 a and 274 a by a plural number of times and averaging, thekTC noise can be suppressed and feedthrough dispersion (FPN component)can be extracted.

The solid-state imaging apparatus 1 can use also a feedthroughdispersion of the column ADC as device unique information.

FIG. 11H is an explanatory view depicting, in a timing chart, operationof the clip circuit 215, the reference signal generation section 216,the current source 217 and the comparator 231 when unique information isgenerated. In the following, operation of elements provided on theoutput line VSL(n−1) or along the output line VSL(n−1) is described.

One horizontal reading out period is started at time t1. At this pointof time, the row selection signal φSEL becomes high and row selection isstarted. At this point of time, since the reset transistor RST is in anON state, the voltage of the floating diffusion section FD is fixed toVDD. Consequently, the dispersion of the floating diffusion section FDis removed. Further, when unique information is generated, the transferpulse φTRG is fixed to the low level. Since the transfer pulse φTRG isfixed to the low level, the transfer transistor TRG is turned off andthe dispersion of the photodiode PD can be removed. Further, theshort-circuiting pulse becomes high and the switches 273 a and 274 a areconnected to each other.

At the point of time of t2, the internal offset of the comparator 275 aand the difference between the VSL voltage and the reference waveformare charged into the input capacitor 272 a, and the operating point ofthe comparator 275 a is initialized.

At time t3, the short-circuiting pulse becomes low, and the switches 273a and 274 a are turned off. Consequently, kTC noise and feedthroughdispersion at the switches 273 a and 274 a are generated.

The period from time t4 to time t5 is a first AD conversion period (ADCperiod 1). During this period of time, the DA converter 232 changes thereference waveform linearly within a predetermined inclination. Then,the comparator 275 a AD converts the reference signal using thereference waveform. Within this ADC period 1, reversal delay of thecomparator 275 a, delay of the reference waveform and clock delay of thecounter occur. It is to be noted that what is indicated by a triangle inFIG. 11H is a reversal timing of the comparator 275 a.

At the point of time of time t6, since the reset transistor RST is in anON state, kTC noise (temporal component) and reset feedthrough noise(FPN component) are retained in the voltage of the floating diffusionsection FD.

The period from time t7 to time t8 is a second AD conversion period (ADCperiod 2). Also during this period, the DA converter 232 changes thereference waveform linearly with a predetermined inclination. Then, thecomparator 275 a AD converts the reference signal using the referencewaveform. Here, the digital value after the conversion similarlyincludes kTC noise and feedthrough dispersion at the switches 273 a and274 a having occurred at time t4 and reversal delay of the comparator275 a, delay of the reference waveform and clock delay of the counterhaving occurred during the ADC period 1. It is to be noted that what isindicated by a triangle in FIG. 11H is a reversal timing of thecomparator 275 a.

Therefore, after the ADC period 2 ends, a difference process between thecount value of the counter 233 during the ADC period 1 and the countvalue of the counter 233 during the ADC period 2 is performed. By thisdifference process, a dispersion occurring in the detection section 218is removed and the kTC noise and reset feedthrough noise retained in thefloating diffusion section FD are detected. By performing detection ofthis kTC noise and feedthrough dispersion by a plural number of timesand averaging, the kTC noise can be suppressed and a feedthroughdispersion (FPN component) can be extracted.

Also a defect of the photodiode PD can be used as the device uniqueinformation. The defect of the photodiode PD can be read out by ordinarydriving. When a defect of the photodiode PD is read out by ordinarydriving, also defect information of the optical signal and the floatingdiffusion section FD is read out simultaneously. The FPN componentsother than them and the kTC noise when the floating diffusion section FDis reset are removed by a CDS process. The defect information of thefloating diffusion section FD is excepted because driving is performedsuch that the detection period becomes as short as possible and besidesthe defect is corrected. If an optical signal is present, then since thedefect information of the photodiode PD is not extracted easily, in thecase where a defect of the photodiode PD is used as the device uniqueinformation, a signal of the photodiode PD is preferably accumulated ina shielded state. In the case where a defect of the photodiode PD isused as the device unique information, a photodiode PD of a shieldedpixel (optical black pixel) may be used.

Since a dark signal by a defect of the photodiode PD has a timedependency, preferably the shutter time is set as long as possible toaccumulate a signal. Further, the photodiode PD generally has a HADstructure (Hole Accumulated Diode structure) and is formed and driven insuch a manner as to be surrounded by Holes. In driving, a negative biasis applied such that the channel of the transfer transistor becomes anaccumulation state (pinning state). This makes it possible to suppressthe dark signal arising from a defect in the proximity of the transfertransistor low.

In the case where the signal is very low or the number of defects isvery small, it is sufficient if, upon signal accumulation, the potentialof the transfer transistor when it is off is set to an intermediatepotential in the positive direction to perform changing from a pinningstate to a depleted state. The dark output arising from a defect in theproximity of the transfer transistor occurs. This makes it possible todetect defect information in the proximity of the photodiode PD and thetransfer transistor and, for example, to handle, for example, a pixeladdress of a level equal to or higher than a desired threshold valuelevel, which is handled as a defect, as device unique information.

Since such defect information has a temperature characteristic(activation energy is approximately 0.55 to 1.1 eV), in order tostabilize the output, it is desirable to set the accumulation timeperiod and the analog gain appropriately on the basis of the temperatureinformation and have and use a temperature correction table for eachdefect to perform correction.

The unique value calculation section 220 calculates a value unique tothe solid-state imaging apparatus 1 (unique value) on the basis of adigital signal sent from the detection section 218. The unique valuecalculation section 220 generates a value having a predetermined bitlength as the unique value. An example of a calculation method of aunique value of the solid-state imaging apparatus 1 by the unique valuecalculation section 220 is hereinafter described in detail. After theunique value calculation section 220 calculates a unique value of thesolid-state imaging apparatus 1, it sends the unique value to theencryption section 222. The unique value generated by the unique valuecalculation section 220 can become a seed that is used in an encryptionprocess by the encryption section 222 or a key itself.

The unique value calculation section 220 may select which one of aplurality of kinds of device unique information is to be adopted. Whenthe unique value calculation section 220 selects device uniqueinformation, it may select which one of kinds of device uniqueinformation is to be adopted by an arithmetic operation on the basis ofthe device unique information or may select which one of kinds of deviceunique information is to be adopted depending upon a random number. Asan alternative, a selection condition when device unique information isto be selected may be stored in a nonvolatile memory. Writing of theselection condition into the nonvolatile memory may be performed onlyonce. The timing of writing into the nonvolatile memory may possibly betime, for example, upon inspection, upon shipment, upon first use or thelike. The unique value calculation section 220 can repetitivelycalculate a unique value using device unique information based on anyproduction dispersion that may occur in a chip of the solid-stateimaging apparatus 1 including device unique information whoseinformation amount is comparatively small. In other words, theinformation amount of the device unique information can be increased.

Further, the unique value calculation section 220 may calculate a uniquevalue by combining a plurality of kinds of device unique informationfrom within device unique information generated by the uniqueinformation generation section 214. By calculating a unique value bycombining a plurality of kinds of device unique information, it becomesless likely to be analyzed in what manner the unique value iscalculated.

Further, a unique value generated by the unique value calculationsection 220 may be temporarily stored in a memory. By storing the uniquevalue generated by the unique value calculation section 220 into thememory, the calculation timing of the unique value is less likely to beanalyzed. In particular, the solid-state imaging apparatus 1 may notgenerate a unique value at a timing of a request for encryption but mayuse a unique value generated in advance in response to a request forencryption. For example, the solid-state imaging apparatus 1 maycalculate a unique value, for example, after a predetermined period oftime elapses after driving upon ordinary imaging is performed. As analternative, the solid-state imaging apparatus 1 may generate a uniquevalue not at a timing of a request for encryption but at a timing atwhich a request for generation of a unique value is received.

Further, the unique value calculation section 220 may average uniquevalues obtained in accordance with the same driving condition. Byaveraging unique values obtained in accordance with the same drivingcondition, noise in the time direction can be suppressed.

The encryption section 222 executes an encryption process of data usinga unique value generated by the unique value calculation section 220.The encryption section 222 may possibly be provided, for example, in thelogic circuit 23014 depicted in FIG. 2. In particular, the encryptionsection 222 uses the unique value generated by the unique valuecalculation section 220 as a seed or a key itself to perform anencryption process of data. What becomes a target of encryption may bethe unique value itself, image information, a feature amount based onthe image information or the like. By performing the encryption processusing the unique value generated by the unique value calculation section220, the solid-state imaging apparatus 1 can encrypt the data verysecurely.

The communication controlling section 224 transmits data to the outsideof the solid-state imaging apparatus 1. The communication controllingsection 224 may perform different processes depending upon whethercaptured image data is outputted or data encrypted by the encryptionsection 222 is outputted.

From within the configuration of the solid-state imaging apparatus 1depicted in FIG. 9, at least the path for processing unique informationis formed such that it does not appear on the surface of the solid-stateimaging apparatus 1. For example, the path for processing uniqueinformation is disposed such that it is covered with a metal film of anupper layer including the outermost layer. The path for processingunique information may be covered with a predetermined shield layer ormay be covered with a wiring line for VDD or VSS. The path forprocessing the unique information may possibly include, for example, theunique information generation section 214, the detection section 218,the unique value calculation section 220 and the encryption section 222.Further, the solid-state imaging apparatus 1 is formed such that a padfor monitoring unique information is not provided on the path forprocessing unique information. By forming the solid-state imagingapparatus 1 in this manner, not only leak of unique information of thesolid-state imaging apparatus 1, which is used for an encryptionprocess, to the outside can be prevented, but if it is tried to analyzethe unique information, then destruction of the solid-state imagingapparatus 1 cannot be avoided, and as a result, analysis of the uniqueinformation is impossible. Further, the solid-state imaging apparatus 1according to the present embodiment generates unique information everytime without retaining the unique information in the inside thereof andperforms an encryption process using a unique value based on thegenerated unique information. Accordingly, the solid-state imagingapparatus 1 according to the present embodiment can carry out a verysecure encryption process.

Since the solid-state imaging apparatus 1 according to the presentembodiment does not retain unique information in the inside thereof, ifthe unique value generated on the basis of the unique informationchanges at each generation, then decoding of encrypted data is disabled.Accordingly, it is demanded that the unique value indicates the samevalue at any time. Accordingly, the solid-state imaging apparatus 1according to the present embodiment may include a function forcorrecting a unique value calculated by the unique value calculationsection 220 on the basis of a signal outputted from the uniqueinformation generation section 214 in response to the temperature of thechip in which the unique information generation section 214 is provided.Further, the solid-state imaging apparatus 1 according to the presentembodiment may include a function for detecting the temperature of thechip in which the unique information generation section 214 is provided.

FIG. 12 is an explanatory view depicting a different functionalconfiguration example of the solid-state imaging apparatus 1 accordingto the present embodiment. FIG. 12 depicts a configuration including achip temperature detection section 226 and a signal correction section228 in addition to the configuration of the solid-state imagingapparatus 1 depicted in FIG. 9.

The chip temperature detection section 226 detects the temperature ofthe chip in which the unique information generation section 214 isprovided. The chip temperature detection section 226 sends informationof the detected temperature of the chip to the signal correction section228. The signal correction section 228 corrects the unique valuecalculated by the unique value calculation section 220 on the basis ofthe temperature, detected by the chip temperature detection section 226,of the chip in which the unique information generation section 214 isprovided. The signal correction section 228 may retain a table in whichcorrection values according to temperatures are stored and determine acorrection value on the basis of the temperature detected by the chiptemperature detection section 226.

3.2. Operation Example

An operation example of the solid-state imaging apparatus according tothe present embodiment is described. FIG. 13 is a flow chart depictingan operation example of the solid-state imaging apparatus according tothe present embodiment. What is depicted in FIG. 13 is an operationexample when the solid-state imaging apparatus 1 calculates a uniquevalue and performs an encryption process using the unique value.

The solid-state imaging apparatus 1 first generates analog uniqueinformation on which a unique value is to be based (step S201). Theanalog unique information is generated by the unique informationgeneration section 214 driven by the driving controlling section 210.

After the analog unique information is generated, the solid-stateimaging apparatus 1 subsequently converts the analog unique informationinto a digital value (step S202). The conversion of the analog uniqueinformation into a digital value is performed by the detection section218. The conversion process of the analog unique information into adigital value by the detection section 218 is such as describedhereinabove.

After the analog unique information is converted into a digital value,the solid-state imaging apparatus 1 subsequently calculates a uniquevalue of the solid-state imaging apparatus 1 using the digital valueafter the conversion (step S203). The calculation of a unique value ofthe solid-state imaging apparatus 1 is performed by the unique valuecalculation section 220.

After the calculation of a unique value of the solid-state imagingapparatus 1 is performed, the solid-state imaging apparatus 1subsequently performs an encryption process of data using the uniquevalue (step S204). The encryption process of data using the unique valueis performed by the encryption section 222.

The solid-state imaging apparatus 1 according to present embodiment cancomplete, by executing the series of operations described above, anencryption process using unique information in the inside thereofwithout outputting the unique information to the outside. Thesolid-state imaging apparatus 1 according to the present embodiment canencrypt and output important information very safely by performing anencryption process using unique information that does not leak to theoutside.

4. Second Embodiment

Subsequently, as a second embodiment of the present disclosure, anexample of a technology that utilizes a physical feature (namely, ahardware feature) of the solid-state imaging apparatus 1 describedhereinabove and generates a unique value (namely, a PUF value) that isunique to the solid-state imaging apparatus 1 and is difficult toduplicate.

4.1. Basic Idea>

First, a characteristic required for the PUF is described, andthereafter, an outline of a basic idea of the technology for generationof a PUF value according to the present embodiment is described.

As described hereinabove, the PUF is a function for outputting a valueunique to a device utilizing a physical feature difficult to duplicate.In the case where it is supposed to utilize a value unique to a devicegenerated utilizing such PUF as just described (namely, a PUF value),for example, as an identifier for identifying an individual device or askey information for an encryption process or the like, reproducibilityand individual differences are demanded as characteristics of the PUFvalue.

Here, the reproducibility indicates a characteristic that, even ifvarious states such as the temperature or the voltage change orconditions regarding time-dependent degradation and so forth of a deviceitself change upon generation or re-calculation of a PUF value, a sameoutput is obtained every time with respect to a predetermined input. Inparticular, ideally it is desirable that, even if such a change of acondition as described above occurs, the same output can be reproducedperfectly every time with respect to a predetermined input. On the otherhand, upon generation and re-calculation of a PUF value, also it ispossible to apply such a technology as error-correcting codes. In thiscase, if the dispersion of an output obtained every time remains withina range correctable with error-correcting codes or the like, thereproducibility of the output may not necessarily be perfect.

Meanwhile, as regards the individual differences, it is preferable thatPUF values generated for a plurality of devices have sufficientdifferences to such a degree that the individual devices can bedistinguished from each other with the PUF values. In the presentembodiment, as regards the individual differences, it is desirable thatentropy of, for example, 128 bits can be secured.

From such presumptions as described above, in the present embodiment,targeting the amplification transistor Tr13 among the transistorsconfiguring each pixel 2 of the solid-state imaging apparatus 1, thedispersion of the threshold voltage Vth of the amplification transistorTr13 is utilized for generation of a PUF value. More particularly, forthe threshold voltage of a transistor, many factors exist which providea dispersion for each device in a production procedure like the filmthickness of the gate oxide film, the size of the transistor or the ionimplantation. Therefore, it is possible to satisfy the requiredcharacteristic of the individual differences described above. Further,since the amplification transistor Tr13 is positioned at a comparativelylater stage among the transistors configuring the pixel 2, it isinclined to be influenced less likely by composite factors. From such acharacteristic as just described, it is possible to satisfy also therequired characteristic for the reproducibility described above.Further, as regards the dispersion of the threshold voltage Vth, it ispossible to acquire the dispersion as an output result of a pixel signalfrom the pixel 2 (in other words, a pixel value), for example, in aprocess for performing compensation for the threshold voltage Vth.

Further, in the present embodiment, it is sufficient if a PUF value isgenerated utilizing a characteristic of a pixel 2 that operates morestably among the pixels 2 of the solid-state imaging apparatus 1. As aparticular example, a characteristic of a pixel 2 included in at leastpart of a so-called OPB (Optical Black) region from within the pixelregion 3 (in other words, an imaging plane) may be utilized forgeneration of a PUF value.

For example, FIG. 14 is an explanatory view illustrating an example ofthe technology for generation of a PUF value according to the presentembodiment and depicts an example of a configuration of the pixel region3 of the solid-state imaging apparatus 1. As depicted in FIG. 14, thepixel region 3 of the solid-state imaging apparatus 1 according to thepresent embodiment includes, for example, an effective pixel region R501and an OPB region R503.

The effective pixel region R501 corresponds to a region in which animaging object image is formed through an optical system such as a lensfrom within the pixel region 3 of the solid-state imaging apparatus 1.In particular, an image signal based on pixel signals (in other words,pixel values) read out from the pixels 2 included in the effective pixelregion R501 from within the pixel region 3 of the solid-state imagingapparatus 1 is outputted as an imaging result of an image.

The OPB region R503 is a region provided in the proximity of theeffective pixel region R501 and shielded by metal or the like. Thepixels 2 included in the OPB region R503 are utilized, for example, formeasurement of a level of a pixel signal that becomes a reference forcorrecting the black level. In particular, by measuring the level of apixel signal outputted from a pixel 2 included in the OPB region R503,it is possible to recognize the level (offset amount) of a signal thatincludes an influence of dark current in a state in which no light isincident or reading out noise. Therefore, ideally the black level can becorrected to 0 by subtracting the measurement value of the level of apixel signal outputted from a pixel 2 in the OPB region R503 (namely, anoffset amount) from an image signal read out from a pixel 2 in theeffective pixel region R501.

As described above, a pixel 2 included in the OPB region R503 is lesslikely to be influenced by light incident through an optical system suchas a lens from the characteristic that it is shielded by the metal orthe like. From such a characteristic as just described, it is possibleto obtain, from a pixel 2 included in the OPB region R503, acomparatively stable output as a light reception result in comparisonwith a pixel 2 included in the effective pixel region R501. In otherwords, utilization of a characteristic of a pixel 2 included in the OPBregion R503 is more effective than that in an alternative case in whicha characteristic of a pixel 2 included in the effective pixel regionR501 is utilized from the point of view that the requirement forreproducibility of a PUF value is satisfied.

Further, a pixel signal outputted from any pixel 2 included in the OPBregion R503 is not outputted as an imaging result of an image.Therefore, it is difficult to infer a characteristic of a pixel 2included in the OPB region R503 from an analysis result of an imageobtained as a result of the imaging. In other words, even if acharacteristic of a pixel 2 included in the OPB region R503 is utilizedfor generation of a PUF value, it is difficult to infer the PUF valuefrom an analysis result of an image obtained as a result of imaging.

Further, since the pixels 2 included in the OPB region R503 need notnecessarily operate normally, they are less likely to be deteriorated incomparison with the pixels 2 included in the effective pixel regionR501. Therefore, the characteristic of the device to be utilized forgeneration of a PUF value is more effective also from the point of viewof the reliability.

Further, the OPB region R503 is a region provided already in theexisting solid-state imaging apparatus 1. Therefore, by utilizing acharacteristic of a pixel 2 included in the OPB region R503 forgeneration of a PUF value, the necessity for providing a region forexclusive use or a device for exclusive use for generating the PUF valueis eliminated.

For example, in the example depicted in FIG. 14, a characteristic of apixel 2 included in the region indicated by reference sign R505 fromamong the pixels 2 included in the OPB region R503 is utilized forgeneration of a PUF value.

Thus, after the characteristics required for the PUF are described, anoutline of the basic idea of the technology for generation of a PUFvalue according to the present embodiment has been described.

4.2. Generation Method of PUF Value

Subsequently, an outline of a generation method of a PUF value in thesolid-state imaging apparatus 1 according to the present embodiment isdescribed.

In the solid-state imaging apparatus 1 according to the presentembodiment, pixels included in a predetermined region (for example, theOPB region) are divided into a plurality of blocks each including one ormore pixels. On the basis of such a configuration as just described, inthe solid-state imaging apparatus 1 according to the present embodiment,one or more blocks specified in accordance with a predeterminedcondition from among the plurality of blocks are utilized for generationof a PUF value. For example, FIG. 15 is an explanatory view illustratingan example the technology for generation of a PUF value in the presentembodiment and depicts an example of the blocks described above. Inparticular, in the example depicted in FIG. 15, 2000×8 pixels aredivided into blocks each including 2×4 pixels, and in this case, thenumber of blocks is 2000.

It is to be noted that, in the case where pixels included in apredetermined region are to be divided into a plurality of blocks, it issufficient if each block is defined such that a plurality of pixels thatshare a predetermined circuit like a so-called AMP circuit are includedin a common block. By adopting such a configuration as just described,the pixels included in each block come to indicate a same tendency of adispersion arising from the circuit shared by the pixels from amongdispersions of output signals from the pixels (namely, of pixel values).

Further, in the solid-state imaging apparatus 1 according to the presentembodiment, a pixel value corresponding to each block is calculated onthe basis of pixel values of one or more pixels included in the block.As a particular example, the total of pixel values of one or more pixelsincluded in each block may be set as a pixel value corresponding to theblock. For example, in the case where, in the example depicted in FIG.15, the pixel value of each pixel is indicated by 10 bits, since oneblock includes 2×4 pixels, the pixel value that is calculated for eachblock and corresponds to the block can be represented as a value of 13bits. It is to be noted that the pixel value calculated for each blockand corresponding to the block is hereinafter referred to also merely as“pixel value for each block.” Further, the pixel value of each pixelcorresponds to a “first pixel value” and the pixel value for each blockcorresponds to a “second pixel value.” It is to be noted that, in thecase where it is defined that each block includes one pixel, the pixelvalue for each block corresponds to the pixel value for each pixel.

On the basis of such a configuration as described above, in thesolid-state imaging apparatus 1 according to the present embodiment,from among a plurality of blocks defined in such a manner as describedabove, a block in which the pixel value for each block is not includedin a predetermined range including an average of the pixel values amongthe plurality of blocks is utilized for generation of a PUF value. Forexample, FIG. 16 is an explanatory view illustrating an example of thetechnology for generation of a PUF value according to the presentembodiment and depicts an example of a distribution of pixel values foreach block among a plurality of blocks. Further, in FIG. 16, referencesign D510 indicates an average value of pixel values for each blockamong the plurality of blocks.

As depicted in FIG. 16, the distribution of pixel values for each blockhas a tendency that it indicates a so-called normal distribution withreference to the average D510 of the pixel values among the plurality ofblocks. On the basis of such a configuration as just described, in thesolid-state imaging apparatus 1 according to the present embodiment, fora block that indicates a pixel value higher than the average D510, “1”is set as a value for generating a PUF value, but for a block thatindicates a pixel value lower than the average D510, “0” is set.

On the other hand, the pixel value for each block sometimes changesevery time (for example, for each frame) by an influence of random noiseand so forth. Therefore, for example, in regard to a block in which thepixel value indicates a value in the proximity of the average D510,there are a case in which the pixel value indicates a value higher thanthe average D510 (namely, “1” is set as a value for generating a PUFvalue) for each frame and another case in which the pixel valueindicates a value lower than the average D510 (namely, “0” is set as avalue for generating a PUF value) for each frame. Taking such acharacteristic as just described into consideration, in the solid-stateimaging apparatus 1 according to the present embodiment, a block inwhich the pixel value for each block is included in a predeterminedrange R511 including the average D510 is excluded from the utilizationtarget for PUF value generation. In other words, a block in which thepixel value for each block is not included in the range R511, that is, ablock in which the pixel value is included in one of the ranges R513 andR515 is specified as a utilization target for PUF value generation. Inparticular, as a value for generating a PUF value, “0” is set to a blockin which the pixel value is included in the range R513, and “1” is setto a block in which the pixel value is included in the range R515.

It is to be noted that it is sufficient if the range R511 depicted inFIG. 16 is set, for example, in response to the standard deviation σ ofpixel values for each block among the plurality of blocks. In this case,a block in which the absolute value of the difference between the pixelvalue for each block and the average D510 of the pixel values among theblocks (namely, the distance between the pixel value for each block andthe average D510) is equal to or higher than a predetermined thresholdvalue is specified as a utilization target for PUF value generation.

Here, in the case where the standard deviation of pixel values of thepixels in a block is represented by σ′, the standard deviation σ′sometimes becomes, for example, approximately 1/20 the standarddeviation σ of the pixel values for each block among the blocks.Thereupon, it is sufficient if the threshold value for the distancebetween the pixel value for each block and the average D510 is set, forexample, around 0.3σ. In this case, in order for the value set inresponse to the pixel value to vary between “0” and “1” in a block inwhich the distance between the pixel value for each block and theaverage D510 exceeds the threshold value, it is necessary for thedispersion of the pixel value to exceed 6σ′.

From such a characteristic as just described, in the solid-state imagingapparatus 1 according to the present embodiment, a block in which thepixel value indicates a value around the average D510 is excluded fromthe utilization target for PUF value generation, and a block in whichthe distance between the pixel value and the average D510 is equal to orgreater than the threshold value is made a utilization target for PUFvalue generation.

It is to be noted that, as the range R511 depicted in FIG. 16 is setnarrower, while the number of blocks that can become a candidate for autilization target for PUF value generation increases, there is atendency that the probability that an error may occur in PUF values tobe generated becomes higher. In contrast, as the range R511 is setwider, while the number of blocks that can become a candidate for autilization target for PUF value generation decreases, it becomespossible to suppress lower the probability that an error may occur inPUF values to be generated. Therefore, for example, the range R511 to beexcluded from the utilization target for PUF value generation may be setin response to an error rate permitted for PUF values to be generated.

It is to be noted that, since information itself of a block specified asa utilization target for PUF value generation is not information thatbecomes a protection target (information having confidentiality) likeso-called secret information, it is sufficient if the information of theblock is stored, for example, into a predetermined storage region in thesolid-state imaging apparatus 1 (for example, into a nonvolatile storageregion).

Now, an example of a method of calculating a value unique to thesolid-state imaging apparatus 1 (namely, a PUF value) in response topixel values for each block is described with reference to FIGS. 16 to18. For example, FIGS. 17 and 18 are explanatory views illustrating anexample of a generation method of a PUF value according to the presentembodiment.

Referring to FIG. 17, reference sign D511 schematically indicates aplurality of blocks into which pixels included in a predetermined regionare divided as described hereinabove with reference to FIG. 15. Further,the numerical value indicated in each block denoted by reference signD511 indicates whether or not the pixel values corresponding to theblock are included in a predetermined range including an average of thepixel values (namely, the range R511 depicted in FIG. 16).

In particular, the solid-state imaging apparatus 1 according to thepresent embodiment successively decides, for each block from apredetermined start position, whether or not the pixel values for eachblock are included in the predetermined range R511 including an averageof the pixel values and associates a value of “0” or “1” with the blockin response to a result of the decision. For example, in the exampledepicted by reference sign D511 of FIG. 17, “0” is associated with ablock in which the pixel value is included in the range R511, and “1” isassociated with a block in which the pixel value is not included in therange R511 (namely, included in the range R513 or R515). In such amanner as described above, the solid-state imaging apparatus 1sequentially executes the decision described above until the number ofblocks in which the pixel value for each block is not included in therange R511 (namely, the number of blocks with which “1” is associated)is specified by a predetermined bit length or more. Then, thesolid-state imaging apparatus 1 causes the positions of the blocks withwhich the “1” is associated to be stored in a predetermined storageregion. It is to be noted that the blocks with which “1” is associatedare made a utilization target for PUF value generation.

Thereafter, the solid-state imaging apparatus 1 compares the pixelvalues of the blocks in which the pixel value for each block is notincluded in the range R511 with the average D510 of pixel values amongthe blocks as depicted in FIG. 17 to specify a value for generating aPUF value corresponding to the block (hereinafter referred to also as“bit value”). In particular, the solid-state imaging apparatus 1 sets“0” as the bit value to each of the target blocks in which the pixelvalue for each block is lower than the average D510 and sets “1” as thebit value to each of the target blocks in which the pixel value ishigher than the average D510. For example, in FIG. 17, reference signD513 schematically depicts a bit value set to each of the blocks thatbecome a utilization target for PUF value generation.

In such a manner as described above, the solid-state imaging apparatus 1secures bit values equal to or greater than the predetermined bit lengthand connects the bit values to generate a PUF value. It is to be notedthat, upon generation of a PUF value, the solid-state imaging apparatus1 may utilize part of the secured series of bit values to calculate anerror-correcting code (ECC) for correcting an error of the PUF valuere-calculated separately and cause the error-correcting code to bestored in a predetermined storage region. In this case, it is sufficientif a rather great number of blocks that become a utilization target forPUF value generation are specified such that bit values that are usedfor calculation of an error-correcting code are secured.

Further, in the case where a PUF value is used, the solid-state imagingapparatus 1 re-calculates the PUF value on the basis of the informationstored in the predetermined storage region. In particular, thesolid-state imaging apparatus 1 specifies blocks that become autilization target for PUF value generation on the basis of theinformation stored in the storage region and reads out pixel valuescorresponding to the blocks (namely, the pixel values for each block).The solid-state imaging apparatus 1 compares the pixel valuescorresponding to the specified blocks with the average D510 of the pixelvalues among the blocks to specify bit values corresponding to theblocks and connects the specified bit values to re-generate a PUF value.Further, at this time, in the case where the error-correcting code forcorrecting an error of the PUF value is stored in the predeterminedstorage region, it is sufficient if the solid-state imaging apparatus 1executes error correction for the PUF value generated again on the basisof the error-correcting code.

The PUF value generated (calculated) in such a manner as described abovecan be utilized, for example, as an identifier for identifying thesolid-state imaging apparatus 1 or as key information for encryptingpredetermined information generated in the solid-state imaging apparatus1.

It is to be noted that, as the pixel value for each block utilized forgeneration of a PUF value, an average of pixel values for each blockbetween a plural number of times of imaging may be utilized. Where sucha configuration as just described is used, it is possible to reduce theinfluence of the dispersion of pixel values for each block by randomnoise or the like (in other words, it is possible to reduce the errorrate of pixel values for each block).

An outline of the generation method of a PUF value in the solid-stateimaging apparatus 1 according to the present embodiment has beendescribed above with reference to FIGS. 15 to 18.

4.3. Functional Configuration>

Now, an example of a functional configuration of the solid-state imagingapparatus 1 according to the present embodiment is described especiallynoticing a portion relating to generation and re-calculation of a PUFvalue unique to the solid-state imaging apparatus 1. For example, FIG.19 is a block diagram depicting an example of a functional configurationof the solid-state imaging apparatus 1 according to the presentembodiment. It is to be noted that, in FIG. 19, in order to furtherfacilitate understanding of a feature of the solid-state imagingapparatus 1 according to the present embodiment, a configurationrelating to generation of a PUF value unique to the solid-state imagingapparatus 1 is depicted while the configuration of the other part is notdepicted.

As depicted in FIG. 19, the solid-state imaging apparatus 1 according tothe present embodiment includes a sensor section 511, an informationprocessing section 512 and a storage section 513.

The sensor section 511 corresponds to the pixel array 3 describedhereinabove with reference to FIG. 1 and photoelectrically convertslight from an imaging object into an electric signal.

The information processing section 512 executes various processesrelating to generation of a PUF value unique to the solid-state imagingapparatus 1. As depicted in FIG. 19, the information processing section512 includes, for example, a block specification section 514, a uniqueinformation acquisition section 515 and a unique value arithmeticoperation section 516. It is to be noted that operation of thecomponents of the information processing section 512 is describedseparately in regard to a case in which a PUF value is generated andanother case in which a PUF value is re-calculated. First, noticing thecase in which a PUF value is generated, operation of the associatedcomponents is described.

The block specification section 514 specifies one or more blocks thatbecome a utilization target for PUF value generation in response to apredetermined condition from among a plurality of blocks into whichpixels included in at least part of regions (for example, the OPBregion) from among a plurality of pixels configuring the sensor section511 are divided. As a particular example, the block specificationsection 514 may specify a block that becomes a utilization target forPUF value generation depending upon whether or not the pixel value foreach value is included in a predetermined range including an average ofthe pixel values among the plurality of blocks. Then, the blockspecification section 514 causes information relating to the specifiedblock to be stored in the storage section 513 hereinafter described. Itis to be noted that the block specification section 514 corresponds toan example of the “specification section.”

The unique information acquisition section 515 acquires, as uniqueinformation, the pixel value for each block from a predetermined numberof blocks or more that become a utilization target for PUF valuegeneration from among a plurality of blocks into which pixels includedin the predetermined region (for example, the OPB region) are divided.It is to be noted that, at this time, the unique information acquisitionsection 515 may specify a block that becomes a utilization target forPUF value generation on the basis of the information stored in thestorage section 513. Then, the unique information acquisition section515 outputs unique information acquired from the predetermined number ofblocks or more that become a utilization target for PUF value generation(namely, pixel values for each block) to the unique value arithmeticoperation section 516.

The unique value arithmetic operation section 516 acquires the uniqueinformation acquired from the predetermined number of blocks or morethat become a utilization target for PUF value generation from theunique information acquisition section 515 and generates a PUF value onthe basis of the acquired unique information. As a particular example,the unique value arithmetic operation section 516 may specify, inresponse to whether or not the unique information acquired for eachblock is greater than a predetermined threshold value (for example, anaverage of pixel values among the blocks), a bit value corresponding tothe block and connect the bit values specified for the individual blocksto generate a PUF value. It is to be noted that the unique valuearithmetic operation section 516 corresponds to an example of the“generation section” that generates (calculates) a value unique to adevice.

Further, when the unique value arithmetic operation section 516generates a PUF value, it may utilize part of the bit values specifiedfor each block to calculate an error-correcting code for correcting anerror of the PUF value re-calculated separately and cause theerror-correcting code to be stored in the storage section 513.

The unique value arithmetic operation section 516 generates a PUF valuein such a manner as described above and outputs the generated PUF valueto a predetermined outputting destination.

The storage section 513 temporarily or permanently retains various kindsof information for allowing the components of the solid-state imagingdevice 1 to execute various processes. The storage section 513 can beconfigured, for example, from a nonvolatile recording medium (forexample, a memory or the like) that can retain storage content even ifpower is not supplied thereto. The storage section 513 may store, forexample, information relating to a block that becomes a utilizationtarget for PUF value generation. Further, an error-correcting code forcorrecting an error of a PUFF value may be stored in the storage section513.

Now, operation of associated components is described noticing a case inwhich a PUF value is re-calculated.

The unique information acquisition section 515 acquires a pixel valuefor each block as unique information from a predetermined number ofblocks or more that become a utilization target for PUF value generationsimilarly as upon generation of a PUF value. Then, the uniqueinformation acquisition section 515 outputs the unique informationacquired individually from the predetermined number of blocks or morethat become a utilization target for PUF value generation to the uniquevalue arithmetic operation section 516.

The unique value arithmetic operation section 516 re-calculates a PUFvalue on the basis of the unique information for the individual blocksacquired from the unique information acquisition section 515 similarlyas upon generation of a PUF value. Further, at this time, in the casewhere an error-correcting code for correcting an error of a PUF value isstored in the storage section 513, the unique value arithmetic operationsection 516 may perform error correction of the re-calculated PUF valueon the basis of the error-correcting code. Then, the unique valuearithmetic operation section 516 outputs the re-calculated PUF value toa predetermined outputting destination.

An example of a functional configuration of the solid-state imagingapparatus 1 according to the present embodiment has been described abovewith reference to FIG. 19 especially noticing a portion that relates togeneration and re-calculation of a PUF value unique to the solid-stateimaging apparatus 1.

4.4. Processing>

Subsequently, as an example of a flow of a series of processes of thesolid-state imaging apparatus 1 according to the present embodiment,processing relating to generation and re-calculation of a PUF valueunique to the solid-state imaging apparatus 1 is described.

First, referring to FIG. 20, an example of processing relating togeneration of a PUF value is described. FIG. 20 is a flow chartdepicting an example of a flow of a series of processes of thesolid-state imaging apparatus 1 according to the present embodiment anddepicts a flow of processing relating to generation of a PUF value.

As depicted in FIG. 20, the solid-state imaging apparatus 1 (blockspecification section 514) first specifies blocks of a predeterminednumber or greater (at least one or more blocks) that are made autilization target for PUF value generation from among a plurality ofblocks into which pixels included in a predetermined region are dividedfrom among a plurality of pixels configuring the sensor section 511(S501). Then, the solid-state imaging apparatus 1 causes informationrelating to the specified blocks (for example, information indicative ofthe position of each of the blocks) to be stored in a predeterminedstorage region (S503).

Then, the solid-state imaging apparatus 1 (unique informationacquisition section 515) acquires, on the basis of the informationstored in the predetermined storage region, pixel values for each blockas unique information from the blocks specified as the utilizationtarget for PUF value generation. Then, the solid-state imaging apparatus1 (unique value arithmetic operation section 516) generates a PUF valueon the basis of the unique information acquired from the predeterminednumber of blocks or more that become a utilization target. As aparticular example, the solid-state imaging apparatus 1 may specify,depending upon whether or not the unique information acquired for eachblock is equal to or greater than a predetermined threshold value, a bitvalue corresponding to the block and connect the bit values specifiedfor the individual blocks to generate a PUF value (S507).

Further, the solid-state imaging apparatus 1 (unique value arithmeticoperation section 516) may utilize part of the bit values specified forthe individual blocks to calculate an error-correcting code forcorrecting an error of a PUF value calculated separately. In this case,the solid-state imaging apparatus 1 may cause the calculatederror-correcting code to be stored in a predetermined storage region(S507).

A PUF value is generated in such a manner as described above, and thegenerated PUF value is outputted to a predetermined outputtingdestination.

An example of processing relating to generation of a PUF value has beendescribed with reference to FIG. 20.

Now, an example of processing relating to re-calculation of a PUF valueis described with reference to FIG. 21. FIG. 21 is a flow chartdepicting an example of a flow of a series of processes of thesolid-state imaging apparatus 1 according to the present embodiment anddepicts a flow of processing relating to re-calculation of a PUF value.

As depicted in FIG. 21, the solid-state imaging apparatus 1 (uniqueinformation acquisition section 515) first specifies the position ofblocks that become a utilization target for PUF value generation on thebasis of the information stored in the predetermined storage region(S511).

Then, the solid-state imaging apparatus 1 (unique informationacquisition section 515) acquires, from the blocks specified as theutilization target for PUF value generation, pixel values for each blockas unique information. Then, the solid-state imaging apparatus 1 (uniquevalue arithmetic operation section 516) re-calculates a PUF value on thebasis of the unique information acquired individually from thepredetermined number of blocks or more that become a utilization targetsimilarly as upon generation of a PUF value (S513)

Further, in the case where an error-correcting code for correcting anerror of a PUF value is stored in a predetermined storage region, thesolid-state imaging apparatus 1 (unique information acquisition section515) may perform error correction of the PUF value re-calculated on thebasis of the error-correcting code (S515).

A PUF value is re-calculated in such a manner as described above, andthe re-calculated PUF value is outputted to a predetermined outputtingdestination.

An example of processing relating to re-calculation of a PUF value hasbeen described with reference to FIG. 21.

4.5. Evaluation

As described above, the solid-state imaging apparatus 1 according to thepresent embodiment specifies, as a target for PUF value generation, atleast one or more blocks from among a plurality of blocks set bydividing pixels included in at least part of a region (for example, anOPB region) of an imaging plane on which a plurality of pixels arearrayed. It is to be noted that each block includes at least one or morepixels. Thus, the solid-state imaging apparatus 1 generates a valueunique to the solid-state imaging apparatus 1 (for example, a PUF value)on the basis of pixel values of pixels included in the specified blocksand a dispersion of pixel values of the pixels among the plurality ofblocks.

By such a configuration as described above, a value unique to thesolid-state imaging apparatus 1 is generated utilizing a physicalfeature (namely, a hardware feature) of the solid-state imagingapparatus 1 difficult to duplicate. Therefore, it is possible to utilizethe unique value, for example, as an identifier for identifying anindividual device or as key information for an encryption process or thelike. Further, since a value unique to the solid-state imaging apparatus1 is generated on the basis of the configuration described above, in thecase where the unique value is utilized as the identifier or the keyinformation, a condition for reproducibility or individual differencesrequired for the identifier or the key information can be satisfiedsufficiently.

It is to be noted that the example described above is an example to thelast, and if a physical feature can be detected for each pixel 2 andbesides it is possible to satisfy a condition for reproducibility orindividual differences required for the PUF value, then the physicalfeature is not necessarily limited only to the dispersion of thethreshold voltage Vth for the amplification transistor Tr13. Forexample, a physical feature of a different transistor other than theamplification transistor Tr13 from among the transistors configuring thepixel 2 may be utilized, and the physical feature is not necessarilylimited only to the dispersion of the threshold voltage Vth. As aparticular example, a detection result of noise generated arising from adevice like a so-called RTS (Random Telegraph Signal) or the like may beutilized for generation of a PUF value.

5. Application Example

Now, an application example of a solid-state imaging apparatus accordingto the present disclosure is described.

5.1. Application Example to Biometric Authentication

As an application example of the technology according to the presentdisclosure, an example of a case in which the solid-state imagingapparatus 1 according to an embodiment of the present disclosure isapplied to biometric authentication for which biometric information isutilized is described. It is to be noted that, in the present set-up, itis assumed that “biometric information” signifies informationrepresenting a feature of a human body such as, for example, an iris, afingerprint, a vein, the face, a handprint, a voice print, a pulse waveand a retina.

Configuration Example 1: Example of Configuration in which BiometricAuthentication is Performed by Solid-State Imaging Apparatus

First, an example of a functional configuration of an imaging apparatusto which the solid-state imaging apparatus according to the presentapplication example is applied, especially, an example of a case inwhich biometric authentication is performed in the solid-state imagingapparatus, is described with reference to FIG. 22. FIG. 22 is anexplanatory view illustrating an application example of the technologyaccording to the present disclosure and is a block diagram depicting anexample of a schematic functional configuration of the imaging apparatusaccording to the present application example.

As depicted in FIG. 22, the imaging apparatus 710 a according to thepresent application example includes a solid-state imaging device 711 aand a main processor 731 a.

The solid-state imaging device 711 a corresponds to the solid-stateimaging apparatus 1 according to the embodiment of the presentdisclosure described hereinabove. As depicted in FIG. 22, thesolid-state imaging device 711 a includes a sensor section 712, aninformation processing section 713, a storage section 719 and aninformation outputting section 720. Further, though not depicted in FIG.22, the solid-state imaging device 711 a may include a registerinterface that transmits and receives a set value to and from theoutside. Here, the “outside” signifies a recording medium into whichimage information generated by an image sensor is stored, a network fortransmitting the image information, an imaging apparatus main body suchas a main processor or a digital camera that processes the imageinformation, a personal computer (PC), a portable terminal, a gamemachine, a non-contacting type IC card such as a FeliCa (registeredtrademark) card or a USB memory.

The sensor section 712 corresponds to the pixel array 3 describedhereinabove with reference to FIG. 1 and performs photoelectricconversion of light from an imaging object into an electric signal.

The information processing section 713 a performs processing foracquired information as occasion demands. As depicted in FIG. 22, theinformation processing section 713 a includes, for example, an imageinformation acquisition section 714, a biometric information acquisitionsection 715, a biometric discrimination section 741, a biometricauthentication section 742, a unique information acquisition section716, a unique value arithmetic operation section 717 and an encryptionprocessing section 718.

The image information acquisition section 714 performs analog to digitalconversion (A/D conversion) for converting the electric signal afterphotoelectric conversion by the sensor section 712 from an analog signalinto a digital signal on the basis of light of an imaging objectcaptured by a user to acquire image information.

The biometric information acquisition section 715 performs A/Dconversion of an electric signal after photoelectric conversion by thesensor section 712 on the basis of light of an imaging object capturedin order to perform biometric authentication of a user to acquirebiometric information.

The unique information acquisition section 716 acquires informationunique to a device configuring the solid-state imaging device 711(hereinafter referred to also as “unique information”). For example, asdescribed hereinabove as the second embodiment, the unique informationacquisition section 716 may acquire pixel values of one or more pixelsincluded in at least part of a region (for example, OPB region) fromamong a plurality of pixels configuring the sensor section 712 as uniqueinformation. Further, at this time, the unique information acquisitionsection 716 may specify pixels that become an acquisition target ofunique information or a block including one or more pixels, for example,on the basis of information retained in advance in the storage section719 hereinafter described.

The unique value arithmetic operation section 717 generates (orcalculates) a value unique to the solid-state imaging device 711 on thebasis of a predetermined function (for example, the PUF described above)using the unique information acquired by the unique informationacquisition section 716 as an input thereto. As a particular example, asdescribed above as the second embodiment, the unique value arithmeticoperation section 717 may generate a PUF value unique to the solid-stateimaging device 711 taking a pixel value of a predetermined pixelacquired as the unique information as an input thereto.

The biometric discrimination section 751 discriminates whether or notthe biometric information acquired by the biometric informationacquisition section 715 is capable of being used for authentication ofthe user.

The biometric authentication section 752 compares the biometricinformation discriminated as information with which the user can beauthenticated and reference information stored in a predeterminedstorage region (for example, the storage section 719 hereinafterdescribed) with each other to authenticate whether or not the user haseligibility for use. It is to be noted that the reference informationmay be in the form encrypted on the basis of a value unique to thesolid-state imaging device 711 (for example, a PUF value) generated bythe unique value arithmetic operation section 717. In this case, thebiometric authentication section 752 may acquire the value unique to thesolid-state imaging device 711 from the unique value arithmeticoperation section 717 and decrypt the reference information on the basisof the acquired value.

The encryption processing section 718 encrypts the biometricauthentication information representing that the user is authenticatedas having eligibility for use to generate cryptographic information andtransmits the cryptographic information to the information outputtingsection 720. It is to be noted that key information for the encryptionmay be encrypted, for example, on the basis of a value (for example, aPUF value) unique to the solid-state imaging device 711 generated by theunique value arithmetic operation section 717. In this case, theencryption processing section 718 may acquire the value unique to thesolid-state imaging device 711 from the unique value arithmeticoperation section 717 such that the key information is decrypted on thebasis of the acquired value.

The information outputting section 720 outputs various kinds ofinformation outputted from the information processing section 713 a tothe outside of the solid-state imaging device 711 a, and includes, forexample, an output switching section 721 and an image informationoutputting section 722.

The output switching section 721 performs switching in regard to whichinformation is to be outputted to the outside of the solid-state imagingdevice 711 a in response to the type of the information inputted fromthe information processing section 713 a. In other words, the outputswitching section 721 has a role of a switch for switching theoutputting destination. Since the solid-state imaging device 711 aincludes the output switching section 721, the user can select whetherimage information described below is to be outputted or cryptographicinformation is to be outputted.

For example, in the case where it is selected that the cryptographicinformation is to be outputted, the output switching section 721performs control such that cryptographic information generated by theencryption processing section 718 (for example, encrypted biometricauthentication information) is transmitted to the main processor 731 athrough a register interface (not depicted) or the like.

In the case where it is selected in the output switching section 721that the image information is to be outputted, the image informationoutputting section 722 receives the image information acquired by theimage information acquisition section 714 and outputs the received imageinformation to the outside of the solid-state imaging device 711 a.

The main processor 731 a receives image information or cryptographicinformation from the solid-state imaging device 711 a and executesvarious processes in response to the type of the received information.As depicted in FIG. 22, the main processor 731 a includes a maincontrolling section 732, an image information inputting section 733 anda development processing section 734.

The main controlling section 732 controls operation of the variouscomponents of the imaging apparatus 710 a. For example, in order tocause the solid-state imaging device 711 a to execute the variousfunctions, the main controlling section 732 transmits control signalscorresponding to the functions to the solid-state imaging device 711 a.Further, in order to implement the various functions of the mainprocessor 731 a, the main controlling section 732 transmits controlsignals corresponding to the functions to various sections in the mainprocessor 731 a.

The image information inputting section 733 acquires image informationoutputted from the solid-state imaging device 711 a in accordance withthe control signal from the main controlling section 732.

The development processing section 734 performs a development process ofan output image on the basis of the image information acquired from thesolid-state imaging device 711 a by the image information inputtingsection 733 in accordance with the control signal from the maincontrolling section 732.

An example of the functional configuration of the imaging apparatus towhich the solid-state imaging apparatus according to the presentapplication example is applied, especially, an example of a case inwhich biometric authentication is performed in the solid-state imagingapparatus, is described above with reference to FIG. 22.

Configuration Example 2: Example of Configuration in which BiometricInformation is Encrypted and Outputted

Now, an example of a functional configuration of an imaging apparatus towhich the solid-state imaging apparatus according to the presentapplication example is applied, especially, an example of a case inwhich an encryption process is performed for biometric informationacquired by the solid-state imaging apparatus and the resultingbiometric information is outputted to the outside, is described withreference to FIG. 23. FIG. 23 is an explanatory view illustrating anapplication example of the technology according to the presentdisclosure and is a block diagram depicting a different example of aschematic functional configuration of the imaging apparatus according tothe present application example. It is to be noted that, in the presentdescription, the functional configuration of the imaging apparatus 710 bdepicted in FIG. 23 is described especially noticing a configurationdifferent from that of the imaging apparatus 710 a described withreference to FIG. 22, and detailed description of the configurationsubstantially similar to that of the imaging apparatus 710 a is omitted.

As depicted in FIG. 23, the imaging apparatus 710 b according to thepresent application example includes a solid-state imaging device 711 band a main processor 731 b. It is to be noted that the solid-stateimaging device 711 b and the main processor 731 b correspond to thesolid-state imaging device 711 a and the main processor 731 a in theimaging apparatus 710 a depicted in FIG. 22, respectively. It is to benoted that, in the example depicted in FIG. 23, in order to makefeatures easier to understand, principally a configuration relating to aprocess that targets biometric information is indicated whileillustration of the configuration relating to the process that targetsthe image information described above is omitted. Therefore, forexample, also in the example depicted in FIG. 23, the imaging apparatus710 b may include the configuration of the image information acquisitionsection 714, the output switching section 721, the image informationoutputting section 722, the image information inputting section 733 andso forth similarly as in the example depicted in FIG. 22.

As depicted in FIG. 23, the solid-state imaging device 711 b includes asensor section 712, an information processing section 713 b, acryptographic information outputting section 723 and a storage section719. The information processing section 713 b further includes, forexample, a biometric information acquisition section 715, a uniqueinformation acquisition section 716, a unique value arithmetic operationsection 717 and an encryption processing section 718. It is to be notedthat the sensor section 712, the storage section 719, the biometricinformation acquisition section 715, the unique information acquisitionsection 716 and the unique value arithmetic operation section 717 aresubstantially similar to the sensor section 712, the storage section719, the biometric information acquisition section 715, the uniqueinformation acquisition section 716 and the unique value arithmeticoperation section 717 in the imaging apparatus 710 a depicted in FIG.22, respectively.

The encryption processing section 718 encrypts biometric information(for example, image information of an iris, a fingerprint, a vein, aface, a handprint, a voice print, a pulse wave, a retina and so forth)acquired by the biometric information acquisition section 715 togenerate cryptographic information and transmits the generatedcryptographic information to the cryptographic information outputtingsection 723. It is to be noted that key information for the encryptionmay be encrypted, for example, on the basis of a value unique to thesolid-state imaging device 711 (for example, a PUF value) generated bythe unique value arithmetic operation section 717. In this case, theencryption processing section 718 may acquire the value unique to thesolid-state imaging device 711 from the unique value arithmeticoperation section 717 and decrypt the key information on the basis ofthe acquired value.

The cryptographic information outputting section 723 receives thecryptographic information generated by performing the encryption processfor the biometric information by the encryption processing section 718and outputs the cryptographic information to the outside of thesolid-state imaging device 711 b.

The main processor 731 b includes a main controlling section 732, acryptographic information inputting section 736, a developmentprocessing section 734 and a biometric authentication section 735.

The main controlling section 732 controls operation of the variouscomponents of the imaging apparatus 710 b. For example, in order tocause the solid-state imaging device 711 b to execute each function, themain controlling section 732 transmits a control signal corresponding tothe function to the solid-state imaging device 711 b. Further, in orderto implement the functions of the main processor 731 b, the maincontrolling section 732 transmits, to each section in the main processor731 b, a control signal corresponding to the function.

The cryptographic information inputting section 736 acquires thecryptographic information outputted from the solid-state imaging device711 b in accordance with the control signal from the main controllingsection 732.

The development processing section 734 decrypts the cryptographicinformation acquired from the solid-state imaging device 711 b by thecryptographic information inputting section 736 in accordance with thecontrol signal from the main controlling section 732, and performs adevelopment process of an output image to be utilized for biometricauthentication on the basis of the biometric information (imageinformation) obtained as a result of the decryption. It is to be notedthat, relating to the key information for decryption of thecryptographic information, it is sufficient if key information similarto the key information utilized for generation of the cryptographicinformation is acquired and stored in a predetermined storage region inadvance. Then, the development processing section 734 outputs the outputimage obtained as a result of the development process to the biometricauthentication section 735.

The biometric authentication section 735 discriminates whether or notthe output image outputted from the development processing section 734is capable of being used for authentication of the user. The biometricauthentication section 735 compares the output image that isdiscriminated as an image capable of being used for authentication ofthe user (in other words, biometric information) and referenceinformation stored in a predetermined storage region with each other toauthenticate whether or not the user has eligibility for use.

An example of a functional configuration of the imaging apparatus towhich the solid-state imaging apparatus according to the presentapplication example is applied, especially, an example of a case inwhich the encryption process is performed for the biometric informationacquired by the solid-state imaging apparatus and the resultingbiometric information is outputted to the outside, is described abovewith reference to FIG. 23.

Configuration Example 3: Different Example of Configuration in whichBiometric Information is Encrypted and Outputted

Now, an example of a functional configuration of an imaging apparatus towhich the solid-state imaging apparatus according to the presentapplication example is applied, especially, a different example of acase in which an encryption process is performed for biometricinformation acquired by the solid-state imaging apparatus and theresulting biometric information is outputted to the outside, isdescribed with reference to FIG. 24. FIG. 24 is an explanatory viewillustrating an application example of the technology according to thepresent disclosure and is a block diagram depicting a different exampleof a schematic functional configuration of the imaging apparatusaccording to the present application example. It is to be noted that, inthe present description, the functional configuration of an imagingapparatus 710 c depicted in FIG. 24 is described especially noticing aconfiguration different from that of the imaging apparatus 710 bdescribed with reference to FIG. 23, and detailed description of aportion substantially similar to that of the imaging apparatus 710 b isomitted.

As depicted in FIG. 24, the imaging apparatus 710 c according to thepresent application example includes a solid-state imaging device 711 cand a main processor 731 c. It is to be noted that the solid-stateimaging device 711 c and the main processor 731 c correspond to thesolid-state imaging device 711 b and the main processor 731 b in theimaging apparatus 710 b depicted in FIG. 23, respectively. It is to benoted that, in the example depicted in FIG. 24, in order to makefeatures easier to understand, principally a configuration relating toprocessing targeting biometric information is depicted and illustrationof a configuration relating to processing targeting image informationdescribed above is omitted. Therefore, for example, also in the exampledepicted in FIG. 24, the components including an image informationacquisition section 714, an output switching section 721, an imageinformation outputting section 722, an image information inputtingsection 733 and so forth may be included similarly as in the exampledepicted in FIG. 22.

As depicted in FIG. 24, the solid-state imaging device 711 c includes asensor section 712, an information processing section 713 c, acryptographic information outputting section 723 and a storage section719. Further, the information processing section 713 c includes, forexample, a biometric information acquisition section 715, a uniqueinformation acquisition section 716, a unique value arithmetic operationsection 717 and an encryption processing section 718.

It is to be noted that the example depicted in FIG. 24 is different fromthe example depicted in FIG. 24 in that a value unique to thesolid-state imaging device 711 c (for example, a PUF value) generated bythe unique value arithmetic operation section 717 is used as keyinformation for performing an encryption process for the biometricinformation acquired by the biometric information acquisition section715. In particular, in the solid-state imaging device 711 c depicted inFIG. 24, operation of the encryption processing section 718 is differentfrom that of the solid-state imaging device 711 b depicted in FIG. 23,and the other components are substantially similar to those of thesolid-state imaging device 711 b.

In particular, the encryption processing section 718 encrypts thebiometric information acquired by the biometric information acquisitionsection 715 to generate cryptographic information using the value uniqueto the solid-state imaging device 711 c generated by the unique valuearithmetic operation section 717 as key information, and transmits thecryptographic information to the cryptographic information outputtingsection 723.

Further, the cryptographic information outputting section 723 receivesthe cryptographic information generated by performing the encryptionprocess for the biometric information by the encryption processingsection 718, and outputs the cryptographic information to the outside ofthe solid-state imaging device 711 c.

The cryptographic information inputting section 736 acquires thecryptographic information outputted from the solid-state imaging device711 c in accordance with a control signal from the main controllingsection 732.

The development processing section 734 decrypts the cryptographicinformation acquired from the solid-state imaging device 711 c by thecryptographic information inputting section 736 in accordance with acontrol signal from the main controlling section 732, and performs adevelopment process of the output image to be utilized for biometricauthentication on the basis of biometric information (image information)obtained as a result of the decryption. It is to be noted that it issufficient if the key information for decryption of the cryptographicinformation, namely, a value unique to the solid-state imaging device711 c (for example, a PUF value), is acquired in advance and stored in apredetermined storage region. Then, the development processing section734 outputs the output image obtained as a result of the developmentprocess to the biometric authentication section 735.

It is to be noted that succeeding processes are similar to those of theimaging apparatus 710 b described with reference to FIG. 23.

As described above, in the solid-state imaging device 711 c depicted inFIG. 24, it is not necessary any more to store the key informationitself to be utilized for encryption of biometric information into thestorage region of the solid-state imaging device 711 c. Therefore, withthe solid-state imaging device 711 c depicted in FIG. 24, the securityperformance relating to protection of biometric information can beenhanced further in comparison with that of the solid-state imagingdevice 711 b described with reference to FIG. 23.

An example of a functional configuration of the imaging apparatus towhich the solid-state imaging apparatus according to the presentapplication example is applied, especially, a different example of acase in which the encryption process is performed for the biometricinformation acquired by the solid-state imaging apparatus and theresulting biometric information is outputted to the outside, isdescribed above with reference to FIG. 24.

5.2. Application Example to Biometric Authentication System

Now, as an application example of the technology according to thepresent disclosure, an application example to a so-called biometricauthentication system in which biometric information acquired by thesolid-state imaging apparatus 1 according to the embodiment of thepresent disclosure is transferred to a server through a network suchthat biometric authentication is executed in the server.

(System Configuration)

First, an example of a schematic system configuration of the biometricauthentication system according to the present application example isdescribed with reference to FIG. 25. FIG. 25 is an explanatory viewillustrating an application example of the technology according to thepresent disclosure and is a block diagram depicting an example aschematic system configuration of the biometric authentication system.

As depicted in FIG. 25, the biometric authentication system 800according to the present application example includes an imagingapparatus 810 and a server 850. Further, the biometric authenticationsystem 800 may include a terminal apparatus 890. The imaging apparatus810, the server 850 and the terminal apparatus 890 are configured suchthat information can be transmitted and received to and from each otherthrough a predetermined network N880. It is to be noted that the kind ofthe network N880 that connects the imaging apparatus 810, the server 850and the terminal apparatus 890 to each other is not limitedspecifically. For example, the network N880 may include the Internet, adedicated line, a LAN (Local Area Network), a WAN (Wide Area Network) orthe like. Further, the network N880 may include a wireless network ormay include a wired network. Further, the network N880 may include aplurality of networks, and at least part of the plurality of networksmay be configured as a wired network. Further, a network for connectingdifferent apparatuses to each other may be set individually. As aparticular example, a network that connects the imaging apparatus 810and the server 850 to each other and another network that connects theserver 850 and the terminal apparatus 890 to each other may beconfigured as networks different from each other.

On the basis of such a configuration as just described, in the biometricauthentication system 800 according to the present application example,for example, biometric information obtained by imaging an imaging objectby the imaging apparatus 810 is transmitted from the imaging apparatus810 to the server 850 such that biometric authentication based on thebiometric information is executed by the server 850. Then, for example,the server 850 executes various processes in response to a result of thebiometric authentication and transmits a result of the execution of theprocesses to the terminal apparatus 890 (for example, a smartphone orthe like) of the user specified on the basis of a result of thebiometric authentication. By such a configuration as just described, aresult of the various processes executed in response to a result of thebiometric authentication based on the imaging result by the imagingapparatus 810 can be confirmed by the terminal apparatus 890 retained bythe user itself.

Then, an example of a functional configuration especially of the imagingapparatus 810 and the server 850 from among the apparatuses included inthe biometric authentication system 800 according to the presentapplication example is described below.

(Functional Configuration of Imaging Apparatus 810)

First, an example of a functional configuration of the imaging apparatus810 according to the present application example is described withreference to FIG. 26. FIG. 26 is an explanatory view illustrating anapplication example of the technology of the present disclosure and is ablock diagram depicting an example of a schematic functionalconfiguration of the imaging apparatus 810 that configures the biometricauthentication system.

As depicted in FIG. 26, the imaging apparatus 810 according to thepresent application example includes a solid-state imaging device 811, amain processor 831 and a communication section 841.

The communication section 841 is a component for performing transmissionand reception of various information to and from a different apparatusthrough a predetermined network by the imaging apparatus 810. Forexample, in the case where transmission and reception of variousinformation are performed to and from an external apparatus through awireless network, the communication section 841 can include acommunication antenna, a RF (Radio Frequency) circuit, a basebandprocessor and so forth. It is to be noted that, in the followingdescription, where the components of the imaging apparatus 810 performtransmission and reception of information to and from a differentapparatus, unless otherwise specified, it is assumed that transmissionand reception of the information are performed through the communicationsection 841.

The solid-state imaging device 811 corresponds to the solid-stateimaging apparatus 1 according to the embodiment of the presentdisclosure described hereinabove. As depicted in FIG. 26, thesolid-state imaging device 811 includes a sensor section 812, aninformation processing section 813, a storage section 819, and aninformation outputting section 820. Further, though not depicted in FIG.26, the solid-state imaging device 811 may include a register interfacefor performing transmission and reception of a set value to and from theoutside. Here, the “outside” signifies a recording medium into whichimage information generated by an image sensor is stored, a network fortransmitting the image information, an imaging apparatus main body suchas a main processor or a digital camera that processes the imageinformation, a personal computer (PC), a portable terminal, a gamemachine, a non-contacting type IC card such as a FeliCa (registeredtrademark) card or a USB memory.

The sensor section 812 corresponds to the pixel array 3 describedhereinabove with reference to FIG. 1 and photoelectrically convertslight from an imaging object into an electric signal.

The information processing section 813 performs processing for acquiredinformation as occasion demands. As depicted in FIG. 26, the informationprocessing section 813 includes, for example, an image informationacquisition section 814, a biometric information acquisition section815, a unique information acquisition section 816, a unique valuearithmetic operation section 817 and an encryption processing section818. It is to be noted that the image information acquisition section814, the biometric information acquisition section 815, the uniqueinformation acquisition section 816 and the unique value arithmeticoperation section 817 are similar to the image information acquisitionsection 714, the biometric information acquisition section 715, theunique information acquisition section 716, and the unique valuearithmetic operation section 717 described with reference to FIG. 22,and therefore, detailed description of them is omitted.

The encryption processing section 818 performs an encryption processbased on a predetermined condition for biometric information of a useracquired by the biometric information acquisition section 815 togenerate cryptographic information and transmits the cryptographicinformation to the information outputting section 820. At this time, theencryption processing section 818 may utilize a value unique to thesolid-state imaging device 811 (for example, a PUF value) generated, forexample, by the unique value arithmetic operation section 817 as a keyfor encryption. Further, the encryption processing section 818 mayutilize key information (for example, a common key) used in an existingencryption method as a key for encryption. It is to be noted that, inthe case where key information that is used in an existing encryptionmethod is utilized, the configuration for generating a value unique tothe solid-state imaging device 811 (for example, the unique informationacquisition section 816 and the unique value arithmetic operationsection 817) may not necessarily be provided.

The storage section 819 includes a nonvolatile recording medium (forexample, a memory or the like) that can retain storage content even ifpower is not supplied thereto and temporarily or permanently regainsvarious kinds of information for allowing the components in thesolid-state imaging device 811 to execute various processes. Forexample, the storage section 819 may retain in advance thereininformation for allowing the unique information acquisition section 816to specify pixels that become an acquisition target of uniqueinformation (or a block including one or more pixels).

The information outputting section 820 outputs various kinds ofinformation outputted from the information processing section 813 to theoutside of the solid-state imaging device 811, and includes, forexample, an output switching section 821, an image informationoutputting section 822 and a cryptographic information outputtingsection 823.

The output switching section 821 performs switching regarding whichinformation is to be outputted to the outside of the solid-state imagingdevice 811 in response to the kind of the information inputted from theinformation processing section 813. In other words, the output switchingsection 821 has a role of a switch for switching the outputtingdestination. Since the solid-state imaging device 811 includes theoutput switching section 821, it is possible to selectively switch whichone of image information acquired by the image information acquisitionsection 814 and cryptographic information obtained by encryptingbiometric information acquired by the biometric information acquisitionsection 815 is to be outputted.

In the case where it is selected by the output switching section 821that the image information is to be outputted, the image informationoutputting section 822 receives image information acquired by the imageinformation acquisition section 814 and outputs the image information tothe outside of the solid-state imaging device 811.

On the other hand, in the case where it is selected by the outputswitching section 821 that the cryptographic information is to beoutputted, the cryptographic information outputting section 823 receivescryptographic information generated by performing the encryption processfor the biometric information by the encryption processing section 818and outputs the cryptographic information to the outside of thesolid-state imaging device 811.

The main processor 831 receives image information or cryptographicinformation from the solid-state imaging device 811 and executes variousprocesses in response to the kind of the received information. Asdepicted in FIG. 26, the main processor 831 includes a main controllingsection 832, an image information inputting section 833, a developmentprocessing section 834, a cryptographic information inputting section835 and a cryptographic information transfer section 836.

The main controlling section 832 controls operation of the variouscomponents of the imaging apparatus 810. For example, in order to causethe solid-state imaging device 811 to execute the various functions, themain controlling section 832 transmits control signals corresponding tothe functions to the solid-state imaging device 811. Further, in orderto implement the functions of the main processor 831, the maincontrolling section 832 transmits control signals corresponding to thefunctions to various sections in the main processor 831.

The image information inputting section 833 acquires image informationoutputted from the solid-state imaging device 811 in accordance with thecontrol signal from the main controlling section 832.

The development processing section 834 performs a development process ofan output image on the basis of the image information acquired from thesolid-state imaging device 811 by the image information inputtingsection 833 in accordance with the control signal from the maincontrolling section 832. Further, the development processing section 834may transmit an output image acquired by the development process to adifferent apparatus connected thereto through a predetermined network(for example, the server 850 or the terminal apparatus 890 depicted inFIG. 25).

The cryptographic information inputting section 835 acquirescryptographic information outputted from the solid-state imaging device811 in accordance with a control signal from the main controllingsection 832.

The cryptographic information transfer section 836 transfers thecryptographic information acquired from the solid-state imaging device811 by the cryptographic information inputting section 835 to apredetermined apparatus connected thereto through a predeterminednetwork (for example, to the server 850 or the like) in accordance witha control signal from the main controlling section 832.

It is to be noted that the configuration depicted in FIG. 26 is anexample to the last, and if the functions of the imaging apparatus 810described above can be implemented, then the configuration of theimaging apparatus 810 is not necessarily restricted to the exampledepicted in FIG. 26.

For example, while, in the example depicted in FIG. 26, the imageinformation outputting section 822 and the cryptographic informationoutputting section 823 are provided separately from each other, theimage information outputting section 822 and the cryptographicinformation outputting section 823 may otherwise be configuredintegrally. In particular, if the main processor 831 discriminates whichkind of information the information to be outputted from the solid-stateimaging device 811 is and the processing can be selectively switched inresponse to the type of the information to be outputted, then theoutputting sections for outputting image information and cryptographicinformation may be commonized. Further, in this case, the imageinformation inputting section 833 and the cryptographic informationinputting section 835 may be configured integrally.

Further, part of the components of the imaging apparatus 810 depicted inFIG. 26 may be provided externally of the imaging apparatus 810.

An example of the functional configuration of the imaging apparatus 810according to the present application example is described above withreference to FIG. 26.

(Functional Configuration of Server 850)

Subsequently, an example of a functional configuration of the server 850according to the present application example is described with referenceto FIG. 27. FIG. 27 is an explanatory view illustrating an applicationexample of the technology according to the present disclosure and is ablock diagram depicting an example of a schematic functionalconfiguration of the server 850 configuring a biometric authenticationsystem.

As depicted in FIG. 27, the server 850 according to the presentapplication example includes a communication section 851, an informationprocessing section 852 and a storage section 857.

The communication section 851 is a component for allowing the server 850to perform transmission and reception of various kinds of information toand from a different apparatus through a predetermined network. Forexample, in the case where the communication section 851 performstransmission and reception of various kinds of information to and froman external apparatus through a wireless network, it can include acommunication antenna, an RF circuit, a baseband processor and so forth.It is to be noted that it is assumed that, in the following description,in the case where each component of the server 850 performs transmissionand reception of information to and from a different apparatus, unlessotherwise specified, the transmission and reception of information areperformed through the communication section 851.

The information processing section 852 decrypts cryptographicinformation transmitted thereto from the different apparatus andexecutes biometric authentication on the basis of biometric informationobtained as a result of the decryption. Further, the informationprocessing section 852 may execute various processes in response to aresult of the biometric authentication. As depicted in FIG. 27, theinformation processing section 852 includes, for example, a decryptionprocessing section 853, a biometric discrimination section 854, abiometric authentication section 855 and a processing execution section856.

The decryption processing section 853 performs a decryption process forcryptographic information transmitted thereto from a different apparatus(for example, from the imaging apparatus 810) on the basis of keyinformation corresponding to the transmission source of thecryptographic information to decrypt the encrypted original information(for example, the biometric information described above).

It is to be noted that, as the key information to be used for decryptionof cryptographic information, for example, a unique value may beutilized for each device of an apparatus of the transmission source (forexample, the solid-state imaging device 811) like the PUF valuedescribed hereinabove. It is to be noted that, as to the unique valuefor each device, it is sufficient if the unique value generated inadvance upon production of the device, for example, is stored in aregion that can be read by the decryption processing section 853 (forexample, the storage section 857 hereinafter described).

Further, as another example, key information (for example, a common keyor the like) that is used in an existing encryption method may beutilized as the key information to be used for decryption ofcryptographic information.

The biometric discrimination section 854 discriminates whether or notthe acquired biometric information can be used for authentication of theuser.

The biometric authentication section 855 compares the biometricinformation discriminated as being capable of authenticating the userand reference information stored in a predetermined storage region (forexample, the storage section 857 hereinafter described) to authenticatewhether or not the user has eligibility for use.

The processing execution section 856 executes values functions (forexample, an application) provided by the server 850. For example, theprocessing execution section 856 extracts a predetermined applicationfrom a predetermined storage section (for example, the storage section857 hereinafter described) in response to a result of the biometricauthentication by the biometric authentication section 855 and executethe extracted application. Further, the processing execution section 856may specify a user in response to a result of the biometricauthentication and transmit information according to a result ofexecution of the application to the terminal apparatus 890 correspondingto the specified user.

The storage section 857 temporarily or permanently retains various kindsof information for allowing the components in the server 850 to executevarious processes. The storage section 857 can include a nonvolatilerecording medium (for example, a memory or the like) whose storagecontent can be retained even if power is not supplied thereto. Further,the storage section 857 may include at least at part thereof a volatilerecording medium.

As a particular example, information that becomes a key for decryptingcryptographic information transmitted from the imaging apparatus 810 maybe retained in the storage section 857. Such information includes, forexample, information indicative of a unique value (for example, a PUFvalue) generated in advance for each imaging apparatus 810 (moreparticularly, for each solid-state imaging device 811).

Further, as another example, reference information that becomes acomparison target of biometric information upon biometric authenticationmay be retained in the storage section 857. Further, management data andso forth for managing data (for example, a library) for executingvarious applications, various kinds of setting and so forth may beretained in the storage section 857.

It is to be noted that the configuration depicted in FIG. 27 is anexample to the last, and if it is possible to implement the functions ofthe server 850 described above, then the configuration of the server 850is not necessarily restricted to the example depicted in FIG. 27. As aparticular example, part of the configurations of the server 850depicted in FIG. 27 may be provided externally of the server 850.Further, as another example, the functions of the server 850 describedabove may be implemented by distributed processing by a plurality ofapparatuses.

An example of the functional configuration of the server 850 accordingto the present application example is described above with reference toFIG. 27.

(Evaluation)

As described above, in the biometric authentication system 800 accordingto the present application example, biometric information acquired bythe solid-state imaging device 811 of the imaging apparatus 810 isoutputted as cryptographic information for which an encryption processhas been performed to the outside of the solid-state imaging device 811.Therefore, in regard to a configuration outside the solid-state imagingdevice 811, even if it is a device in the imaging apparatus 810, in thecase where it does not retain key information for decryption, it isdifficult for the device to decrypt cryptographic information outputtedfrom the solid-state imaging device 811. In particular, in the biometricauthentication system 800 described above, biometric informationacquired by the solid-state imaging device 811 is propagated asencryption information in a route in which it is outputted from thesolid-state imaging device 811 until it is received by the server 850.

Further, for encryption of biometric information, a value unique to theindividual solid-state imaging device 811, which is generated (orcalculated) utilizing a physical feature difficult to duplicate like aPUF value can be utilized as key information.

By such a configuration as described above, with the biometricauthentication system 800 according to the present application example,the security performance relating to protection of biometric informationof a user acquired as a result of imaging by the imaging apparatus 810can be improved further.

5.3. Application Example to Mobile Body

The technology according to the present disclosure (present technology)can be applied to various products. For example, the technologyaccording to the present disclosure may be implemented as an apparatusthat is incorporated in any kind of mobile body of an automobile, anelectric car, a hybrid electric car, a motorcycle, a bicycle, a personalmobility, an airplane, a drone, a ship, a robot and so forth.

FIG. 28 is a block diagram depicting an example of schematicconfiguration of a vehicle control system as an example of a mobile bodycontrol system to which the technology according to an embodiment of thepresent disclosure can be applied.

The vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example depicted in FIG. 28, the vehicle control system 12000includes a driving system control unit 12010, a body system control unit12020, an outside-vehicle information detecting unit 12030, anin-vehicle information detecting unit 12040, and an integrated controlunit 12050. In addition, a microcomputer 12051, a sound/image outputsection 12052, and a vehicle-mounted network interface (I/F) 12053 areillustrated as a functional configuration of the integrated control unit12050.

The driving system control unit 12010 controls the operation of devicesrelated to the driving system of the vehicle in accordance with variouskinds of programs. For example, the driving system control unit 12010functions as a control device for a driving force generating device forgenerating the driving force of the vehicle, such as an internalcombustion engine, a driving motor, or the like, a driving forcetransmitting mechanism for transmitting the driving force to wheels, asteering mechanism for adjusting the steering angle of the vehicle, abraking device for generating the braking force of the vehicle, and thelike.

The body system control unit 12020 controls the operation of variouskinds of devices provided to a vehicle body in accordance with variouskinds of programs. For example, the body system control unit 12020functions as a control device for a keyless entry system, a smart keysystem, a power window device, or various kinds of lamps such as aheadlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or thelike. In this case, radio waves transmitted from a mobile device as analternative to a key or signals of various kinds of switches can beinput to the body system control unit 12020. The body system controlunit 12020 receives these input radio waves or signals, and controls adoor lock device, the power window device, the lamps, or the like of thevehicle.

The outside-vehicle information detecting unit 12030 detects informationabout the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicle information detecting unit 12030is connected with an imaging section 12031. The outside-vehicleinformation detecting unit 12030 makes the imaging section 12031 imagean image of the outside of the vehicle, and receives the imaged image.On the basis of the received image, the outside-vehicle informationdetecting unit 12030 may perform processing of detecting an object suchas a human, a vehicle, an obstacle, a sign, a character on a roadsurface, or the like, or processing of detecting a distance thereto.

The imaging section 12031 is an optical sensor that receives light, andwhich outputs an electric signal corresponding to a received lightamount of the light. The imaging section 12031 can output the electricsignal as an image, or can output the electric signal as informationabout a measured distance. In addition, the light received by theimaging section 12031 may be visible light, or may be invisible lightsuch as infrared rays or the like.

The in-vehicle information detecting unit 12040 detects informationabout the inside of the vehicle. The in-vehicle information detectingunit 12040 is, for example, connected with a driver state detectingsection 12041 that detects the state of a driver. The driver statedetecting section 12041, for example, includes a camera that images thedriver. On the basis of detection information input from the driverstate detecting section 12041, the in-vehicle information detecting unit12040 may calculate a degree of fatigue of the driver or a degree ofconcentration of the driver, or may determine whether the driver isdozing.

The microcomputer 12051 can calculate a control target value for thedriving force generating device, the steering mechanism, or the brakingdevice on the basis of the information about the inside or outside ofthe vehicle which information is obtained by the outside-vehicleinformation detecting unit 12030 or the in-vehicle information detectingunit 12040, and output a control command to the driving system controlunit 12010. For example, the microcomputer 12051 can perform cooperativecontrol intended to implement functions of an advanced driver assistancesystem (ADAS) which functions include collision avoidance or shockmitigation for the vehicle, following driving based on a followingdistance, vehicle speed maintaining driving, a warning of collision ofthe vehicle, a warning of deviation of the vehicle from a lane, or thelike.

In addition, the microcomputer 12051 can perform cooperative controlintended for automatic driving, which makes the vehicle to travelautonomously without depending on the operation of the driver, or thelike, by controlling the driving force generating device, the steeringmechanism, the braking device, or the like on the basis of theinformation about the outside or inside of the vehicle which informationis obtained by the outside-vehicle information detecting unit 12030 orthe in-vehicle information detecting unit 12040.

In addition, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of the information about theoutside of the vehicle which information is obtained by theoutside-vehicle information detecting unit 12030. For example, themicrocomputer 12051 can perform cooperative control intended to preventa glare by controlling the headlamp so as to change from a high beam toa low beam, for example, in accordance with the position of a precedingvehicle or an oncoming vehicle detected by the outside-vehicleinformation detecting unit 12030.

The sound/image output section 12052 transmits an output signal of atleast one of a sound and an image to an output device capable ofvisually or auditorily notifying information to an occupant of thevehicle or the outside of the vehicle. In the example of FIG. 28, anaudio speaker 12061, a display section 12062, and an instrument panel12063 are illustrated as the output device. The display section 12062may, for example, include at least one of an on-board display and ahead-up display.

FIG. 29 is a diagram depicting an example of the installation positionof the imaging section 12031.

In FIG. 29, the imaging section 12031 includes imaging sections 12101,12102, 12103, 12104, and 12105.

The imaging sections 12101, 12102, 12103, 12104, and 12105 are, forexample, disposed at positions on a front nose, sideview mirrors, a rearbumper, and a back door of the vehicle 12100 as well as a position on anupper portion of a windshield within the interior of the vehicle. Theimaging section 12101 provided to the front nose and the imaging section12105 provided to the upper portion of the windshield within theinterior of the vehicle obtain mainly an image of the front of thevehicle 12100. The imaging sections 12102 and 12103 provided to thesideview mirrors obtain mainly an image of the sides of the vehicle12100. The imaging section 12104 provided to the rear bumper or the backdoor obtains mainly an image of the rear of the vehicle 12100. Theimaging section 12105 provided to the upper portion of the windshieldwithin the interior of the vehicle is used mainly to detect a precedingvehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, orthe like.

Incidentally, FIG. 29 depicts an example of photographing ranges of theimaging sections 12101 to 12104. An imaging range 12111 represents theimaging range of the imaging section 12101 provided to the front nose.Imaging ranges 12112 and 12113 respectively represent the imaging rangesof the imaging sections 12102 and 12103 provided to the sideviewmirrors. An imaging range 12114 represents the imaging range of theimaging section 12104 provided to the rear bumper or the back door. Abird's-eye image of the vehicle 12100 as viewed from above is obtainedby superimposing image data imaged by the imaging sections 12101 to12104, for example.

At least one of the imaging sections 12101 to 12104 may have a functionof obtaining distance information. For example, at least one of theimaging sections 12101 to 12104 may be a stereo camera constituted of aplurality of imaging elements, or may be an imaging element havingpixels for phase difference detection.

For example, the microcomputer 12051 can determine a distance to eachthree-dimensional object within the imaging ranges 12111 to 12114 and atemporal change in the distance (relative speed with respect to thevehicle 12100) on the basis of the distance information obtained fromthe imaging sections 12101 to 12104, and thereby extract, as a precedingvehicle, a nearest three-dimensional object in particular that ispresent on a traveling path of the vehicle 12100 and which travels insubstantially the same direction as the vehicle 12100 at a predeterminedspeed (for example, equal to or more than 0 km/hour). Further, themicrocomputer 12051 can set a following distance to be maintained infront of a preceding vehicle in advance, and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), or the like. It is thuspossible to perform cooperative control intended for automatic drivingthat makes the vehicle travel autonomously without depending on theoperation of the driver or the like.

For example, the microcomputer 12051 can classify three-dimensionalobject data on three-dimensional objects into three-dimensional objectdata of a two-wheeled vehicle, a standard-sized vehicle, a large-sizedvehicle, a pedestrian, a utility pole, and other three-dimensionalobjects on the basis of the distance information obtained from theimaging sections 12101 to 12104, extract the classifiedthree-dimensional object data, and use the extracted three-dimensionalobject data for automatic avoidance of an obstacle. For example, themicrocomputer 12051 identifies obstacles around the vehicle 12100 asobstacles that the driver of the vehicle 12100 can recognize visuallyand obstacles that are difficult for the driver of the vehicle 12100 torecognize visually. Then, the microcomputer 12051 determines a collisionrisk indicating a risk of collision with each obstacle. In a situationin which the collision risk is equal to or higher than a set value andthere is thus a possibility of collision, the microcomputer 12051outputs a warning to the driver via the audio speaker 12061 or thedisplay section 12062, and performs forced deceleration or avoidancesteering via the driving system control unit 12010. The microcomputer12051 can thereby assist in driving to avoid collision.

At least one of the imaging sections 12101 to 12104 may be an infraredcamera that detects infrared rays. The microcomputer 12051 can, forexample, recognize a pedestrian by determining whether or not there is apedestrian in imaged images of the imaging sections 12101 to 12104. Suchrecognition of a pedestrian is, for example, performed by a procedure ofextracting characteristic points in the imaged images of the imagingsections 12101 to 12104 as infrared cameras and a procedure ofdetermining whether or not it is the pedestrian by performing patternmatching processing on a series of characteristic points representingthe contour of the object. When the microcomputer 12051 determines thatthere is a pedestrian in the imaged images of the imaging sections 12101to 12104, and thus recognizes the pedestrian, the sound/image outputsection 12052 controls the display section 12062 so that a squarecontour line for emphasis is displayed so as to be superimposed on therecognized pedestrian. The sound/image output section 12052 may alsocontrol the display section 12062 so that an icon or the likerepresenting the pedestrian is displayed at a desired position.

An example of the vehicle controlling system to which the technologyaccording to the present disclosure can be applied has been described.The technology according to the present disclosure can be applied to theimaging section 12031 from within the configuration described above. Inparticular, the solid-state imaging apparatus 1 depicted in FIG. 1 canbe applied to the imaging section 12031. By applying the technologyaccording to the present disclosure to the imaging section 12031, forexample, it is possible to perform encryption of various kinds ofinformation acquired by the imaging section 12031 (for example, imageinformation obtained as a result of imaging or the like) on the basis ofinformation unique to the device (solid-state imaging apparatus) in theinside of the imaging section 12031. This makes it possible, forexample, to further improve the security in regard to protection ofinformation acquired by the imaging section 12031.

6. Conclusion

Although the preferred embodiments of the present disclosure have beendescribed in detail with reference to the accompanying drawings, thetechnical scope of the present disclosure is not limited to suchexamples as described above. It is apparent that various alterationexamples or modification examples can be conceived within the categoryof the technical idea described in the claims by persons who have commonknowledge in the technical field of the present disclosure, and it isrecognized that also such alteration examples or modification examplesnaturally belong to the technical scope of the present disclosure.

Further, the advantageous effects described in the present specificationare explanatory or exemplary but not restrictive to the last. In short,the technology according to the present disclosure can demonstrate otheradvantageous effects apparent to those skilled in the art from thedescription of the present specification together with or in place ofthe advantageous effects described above.

It is to be noted that also such configurations as described belowbelong to the technical scope of the present disclosure.

(1)

An information processing apparatus, including:

-   -   a specification section specifying, from among a plurality of        blocks that are set by dividing pixels included in at least a        partial region of a pixel region having a plurality of pixels        arrayed therein and each of which includes at least one or more        of the pixels, at least one or more of the blocks; and    -   a generation section generating a unique value based on pixel        values of the pixels included in the specified blocks and a        dispersion of the pixel values of the pixels among the plurality        of blocks.        (2)

The information processing apparatus according to (1) above, in whichthe specification section specifies the blocks in each of which a secondpixel value that is calculated based on first pixel values that are thepixel values of the one or more pixels included in the blocks andcorresponds to the blocks is not included in a given range including anaverage of the second pixel values among the plurality of blocks.

(3)

The information processing apparatus according to (2) above, in whichthe generation section generates the unique value based on the secondpixel values corresponding to the specified blocks.

(4)

The information processing apparatus according to (3) above, in whichthe generation section determines at least some of values for generatingthe unique value in response to a result of comparison between thesecond pixel values corresponding to the specified blocks and theaverage.

(5)

The information processing apparatus according to any one of (2) to (4)above, in which the given range is set in response to a dispersion ofthe second pixel values among the plurality of blocks.

(6)

The information processing apparatus according to any one of (2) to (5)above, in which the given range is defined in response to setting forerror correction of the generated unique value.

(7)

The information processing apparatus according to any one of (1) to (6)above, in which the partial region is a region of at least part of anOPB (Optical Black) region.

(8)

The information processing apparatus according to any one of (1) to (7)above, in which the blocks are set by dividing the pixels included inthe region for each of one or more pixels that share a given circuit.

(9)

The information processing apparatus according to any one of (1) to (8)above, in which the unique value is generated based on the pixel valuesaccording to a characteristic of a threshold voltage of a giventransistor in the pixels included in the specified blocks.

(10)

The information processing apparatus according to (9) above, in which

-   -   each of the pixels includes at least three transistors including        a transfer transistor that transfers charge of a photoelectric        conversion element to a floating diffusion, an amplification        transistor that receives a potential of the floating diffusion        and outputs the potential to a signal line, and a reset        transistor that controls the potential of the floating        diffusion, and    -   the unique value is generated based on the pixel value according        to the characteristic of the threshold voltage of the        amplification transistor.        (11)

The information processing apparatus according to any one of (1) to (10)above, in which the generation section generates the unique value usingan average value of the pixel values of the pixels among a plural numberof times of imaging as the pixel values of the pixels.

(12)

The information processing apparatus according to any one of (1) to (11)above, including:

-   -   an encryption processing section performing an encryption        process for desired information using the generated unique value        as key information.        (13)

The information processing apparatus according to any one of (1) to (12)above, in which the unique value is outputted as an identifier to anoutside.

(14)

An information processing method executed by a computer, including:

-   -   specifying, from among a plurality of blocks that are set by        dividing pixels included in at least a partial region of a pixel        region having a plurality of pixels arrayed therein and each of        which includes at least one or more of the pixels, at least one        or more of the blocks; and    -   generating a unique value based on pixel values of the pixels        included in the specified blocks and a dispersion of the pixel        values of the pixels among the plurality of blocks.        (15)

A recording medium on which a program is recorded, the program causing acomputer to execute:

-   -   specifying, from among a plurality of blocks that are set by        dividing pixels included in at least a partial region of a pixel        region having a plurality of pixels arrayed therein and each of        which includes at least one or more of the pixels, at least one        or more of the blocks; and    -   generating a unique value based on pixel values of the pixels        included in the specified blocks and a dispersion of the pixel        values of the pixels among the plurality of blocks.

REFERENCE SIGNS LIST

-   1: Solid-state imaging apparatus-   2: Pixel-   3: Pixel array-   4: Vertical driving circuit-   5: Column signal processing circuit-   6: Horizontal driving circuit-   7: Outputting circuit-   8: Control circuit-   9: Vertical signal line-   10: Horizontal signal line-   11: Semiconductor substrate-   12: Input/output terminal

1. An information processing apparatus, comprising: a specificationsection specifying, from among a plurality of blocks that are set bydividing pixels included in at least a partial region of a pixel regionhaving a plurality of pixels arrayed therein and each of which includesat least one or more of the pixels, at least one or more of the blocks;and a generation section generating a unique value based on pixel valuesof the pixels included in the specified blocks and a dispersion of thepixel values of the pixels among the plurality of blocks.
 2. Theinformation processing apparatus according to claim 1, wherein thespecification section specifies the blocks in each of which a secondpixel value that is calculated based on first pixel values that are thepixel values of the one or more pixels included in the blocks andcorresponds to the blocks is not included in a given range including anaverage of the second pixel values among the plurality of blocks.
 3. Theinformation processing apparatus according to claim 2, wherein thegeneration section generates the unique value based on the second pixelvalues corresponding to the specified blocks.
 4. The informationprocessing apparatus according to claim 3, wherein the generationsection determines at least some of values for generating the uniquevalue in response to a result of comparison between the second pixelvalues corresponding to the specified blocks and the average.
 5. Theinformation processing apparatus according to claim 2, wherein the givenrange is set in response to a dispersion of the second pixel valuesamong the plurality of blocks.
 6. The information processing apparatusaccording to claim 2, wherein the given range is defined in response tosetting for error correction of the generated unique value.
 7. Theinformation processing apparatus according to claim 1, wherein thepartial region is a region of at least part of an OPB (Optical Black)region.
 8. The information processing apparatus according to claim 1,wherein the blocks are set by dividing the pixels included in the regionfor each of one or more pixels that share a given circuit.
 9. Theinformation processing apparatus according to claim 1, wherein theunique value is generated based on the pixel values according to acharacteristic of a threshold voltage of a given transistor in thepixels included in the specified blocks.
 10. The information processingapparatus according to claim 9, wherein each of the pixels includes atleast three transistors including a transfer transistor that transferscharge of a photoelectric conversion element to a floating diffusion, anamplification transistor that receives a potential of the floatingdiffusion and outputs the potential to a signal line, and a resettransistor that controls the potential of the floating diffusion, andthe unique value is generated based on the pixel value according to thecharacteristic of the threshold voltage of the amplification transistor.11. The information processing apparatus according to claim 1, whereinthe generation section generates the unique value using an average valueof the pixel values of the pixels among a plural number of times ofimaging as the pixel values of the pixels.
 12. The informationprocessing apparatus according to claim 1, comprising: an encryptionprocessing section performing an encryption process for desiredinformation using the generated unique value as key information.
 13. Theinformation processing apparatus according to claim 1, wherein theunique value is outputted as an identifier to an outside.
 14. Aninformation processing method executed by a computer, comprising:specifying, from among a plurality of blocks that are set by dividingpixels included in at least a partial region of a pixel region having aplurality of pixels arrayed therein and each of which includes at leastone or more of the pixels, at least one or more of the blocks; andgenerating a unique value based on pixel values of the pixels includedin the specified blocks and a dispersion of the pixel values of thepixels among the plurality of blocks.
 15. A recording medium on which aprogram is recorded, the program causing a computer to execute:specifying, from among a plurality of blocks that are set by dividingpixels included in at least a partial region of a pixel region having aplurality of pixels arrayed therein and each of which includes at leastone or more of the pixels, at least one or more of the blocks; andgenerating a unique value based on pixel values of the pixels includedin the specified blocks and a dispersion of the pixel values of thepixels among the plurality of blocks.